ASK THE RABBI

We will look at the origins, rationale and standing of this drasha and then apply Torah values to deal with your question.

The Mateh Moshe (833) is an early source (late 16^th century) for the minhag of the Shabbat Shuva derasha (in his time they had one before Rosh Hashana as well), with the stated purpose being to inspire the people toward teshuva. He brings a precedent from a midrash (I did not find the exact text) for a special drasha’s importance: “Hashem said that when the chacham sits and is doresh, I forgive Israel’s sins.”

There is another approach – that it is a fulfillment of Chazal’s instruction (Pesachim 6a) to learn/teach the practicalities of each holiday an appropriate time before the holiday (see Kaf Hachayim, Orach Chayim 429:2). Some who take this approach posit that the drasha on Shabbat Shuva should also address the laws of the imminent holiday of Sukkot (see Magen Avraham 429:1).

Many rabbis have a tradition that combines both elements – the drasha was broken up between parts that focus on Halacha and inspiration, respectively. Each rabbi modulates between them according to his style, the topic, or the local needs.

As far as your own learning compared to the drasha, one factor is whether you will get to focus on Yom Kippur on your own. Chazal wanted everyone to have “doses” of both inspiration to do teshuva and diving into halachic topics at this time, as important as your regular learning is. This is apparently despite the fact that generally it is worthwhile to learn “where your heart desires” (Avoda Zara 19a).

However, the more poignant matters relate to personal and communal responsibility. The general concept of b’rov am hadrat melech (Hashem is honored by large groups), while often applied to tefilla, can apply also to Torah study (the mitzva of hakhel is a prototype). Sources imply that the drashot of Shuva and Hagadol have modeled this concept for several centuries. While an individual is only one person, everyone is responsible to be part of the tzibbur. Since you are more learned than most, your presence could be more impactful than most.

Perhaps more importantly, these drashot have a high profile regarding the position of the communal rabbi. Historically, many rabbinic contracts mentioned the need and the exclusive right to deliver the local Shabbat Shuva drasha. This follows ancient precedent of the weekly drasha (see Rashi, Devarim 32:44 regarding the transition between Moshe and Yehoshua and Berachot 28a regarding the drasha as a litmus test of rabbinic leadership between R. Gamliel and R. Elazar ben Azaria). Even today, attendance at these drashot can serve as a referendum on the respect due the rav and whether he is delivering admirably in his public role. When a learned member of the community “votes with his feet” with his absence, he likely undercuts the rabbi, with the dynamics of several elements determining whether this is in a minor or a major way. The gemara (Berachot 18b) tells a scary story of the punishment of the Amora Levi for opting out, apparently to optimize his learning, of the shiur of R. Afes, whose position as Rosh Yeshiva was slightly controversial (see Ketubot 103b).

While we try to be extra careful about all mitzvot during Aseret Y’mei Teshuva, the importance of doing so for mitzvot bein adam lachaveiro is particularly stressed (Yoma 85b). Therefore, the default position is that you should make every reasonable effort to go to the drasha and hope that you get more out of it than you expect. A notable exception would be in a case that the rabbi told you that you should not feel a need to go, AND it is clear to the community that the drasha is focused on a basic level of presentation, for the community’s level, and that you are on a different plane.

One should not fast in the morning until chatzot on Shabbat (Shulchan Aruch, Orach Chayim 288:1) and Yom Tov (Mishna Berura 288:2). Considering that one generally must not eat before davening (Shulchan Aruch, OC 89:3) and the long davening of Rosh Hashana (=RH), this raises a challenge.

One solution is the claim that the need to eat by chatzot does not apply to RH (see Mishna Berura 597:1), because of its different nature compared to the three regalim. First, there are opinions (see Rama, OC 597:3) that there is value in fasting on RH, the Day of Judgment. Although we do not accept that approach, it may justify at least not eating until chatzot (Mateh Ephrayim 597:2). Another reason to be lenient on late eating is that since it is appropriate to say many prayers, late eating is a justifiable price (see Magen Avraham 584:4; Yam Shel Shlomo, Beitza 2:4).

There are, though, opinions that one should eat before chatzot even on RH. One solution is to rely on drinking water or tea (permitted before davening – Shulchan Aruch, OC 89:3) before davening to forestall the fast (Eleph Hamagen 597:2; see opinions in Dirshu 597:7 on whether this is enough), for at least six hours from the drinking. As you know, some shuls solve the problem by having a Kiddush after Shacharit. It is debated whether it is permitted to eat a snack before a special daytime mitzva (see Magen Avraham 652:4 regarding before lulav; Mikraei Kodesh (Frank), RH 29 regarding shofar). We will not go further into that debate, with its legitimate minhagim, and will focus on your question – RH on Shabbat.

On Shabbat, the scales lean more toward allowing and/or encouraging Kiddush before Musaf. For one thing, on Shabbat there is no shofar blowing to avoid preceding. Admittedly, many say not to eat too much before any Shabbat Musaf (see development in this column, Shelach 5783). The Shulchan Aruch (OC 286:3) allows “tasting,” which in a parallel context (see Shulchan Aruch, OC 639:2) means up to a k’beitza (size of an egg) of bread and any amount of “fruit.” Poskim posit that a k’beitza is the limit for pat haba’ah b’kisnin (baked grain-based foods, e.g., cake). There is less certainty regarding limits on grain-based cooked foods (e.g., cholent) (see Shemirat Shabbat K’hilchata 52:(52); Ishei Yisrael 36:76). There is no limit on non-alcoholic beverages (ibid.). The grounds we mentioned for the possibility of being more lenient apply here as well. Thus, with good cause, a shul could provide a light Kiddush menu and not be overly concerned if people eat more than ideal. Do realize that there is also a minimum for how much to eat, for the Kiddush to count (see Shulchan Aruch, OC 273:5)

The major point is that while the “leniency” for partial fasting is plausible on RH, it is forbidden on Shabbat. Therefore, some poskim are insistent that one eat before chatzot when RH falls on Shabbat (Yam Shel Shlomo ibid.; Mishna Berura 584:5). So why do many shuls not make Kiddush before RH/Shabbat Musaf? Rav M. Willig (Am Mordechai, Moadim 3) explains and supports the practice of not having this Kiddush as follows. The Maharil, accepted by the Rama (584:1) allows davening past chatzot without eating because the long davening is a mitzva that applies even if RH is on Shabbat. The Mishna Berura followed the Yam Shel Shlomo who justified late eating on RH because eating is not crucial on RH, and therefore requires pre-chatzot eating when it falls on Shabbat. Therefore, an early Kiddush makes more sense on RH/Shabbat, but is not clearly required. Considering that RH Musaf is shorter on Shabbat, you might finish before chatzot.

A major factor to consider is the Kiddush’s impact on your minyan, which can be positive (e.g., gives strength for Musaf with kavana) or negative (e.g., hard to be intense in Musaf after socializing).

Let us review the rules of “better places,” which are explicit in classical sources, and then broach your excellent question about investing a few seconds.

The gemara (Berachot 4a) presents “Yeh’yu l’ratzon…” as the end of Shemoneh Esrei. The Rashba (VII:405, accepted as halacha by the Shulchan Aruch, Orach Chayim 122:1) says due to this that if one finished Shemoneh Esrei but did not say Yeh’yu L’ratzon, he may not answer Kaddish and Kedusha. After Yeh’yu L’ratzon, it is possible to answer to these devarim shebekedusha and other mitzva responses (Mishna Berura 122:1), as one is considered basically finished with Shemoneh Esrei.

It is an old practice (see Berachot 17a) to recite various tachanunim after Shemoneh Esrei before stepping back, and the one that is now standard, although not required, is “Elokai neztor …”. There are different minhagim on whether to recite Yeh’yu L’ratzon before or after Elokai Netzor (or both). For someone like you who sometimes needs to finish Shemoneh Esrei prematurely, there is more logic to do it before.

During Elokai Netzor, one can answer only selectively, like one who is in the midst of the berachot of Kri’at Shema (Shulchan Aruch ibid.). Specifically, one can answer only “Amen Y’hei sh’mei rabba …” and the amen to “… da’amiran b’olma,” and, in Kedusha, “Kaddosh…” and “Baruch k’vod …” (Mishna Berura 66:17).  It is best to skip the rest of Elokai Netzor and take the steps back (Shulchan Aruch ibid.) or at least say Yeh’yu l’ratzon and be ready for the steps (Mishna Berura 122:6). Then you may do all the responses of Kaddish and Kedusha or actually any amen that arises (ibid. 4).

After seeing that post-Shemoneh Esrei allows mitzva responses, let us look at the “demands” of Kaddish to focus on it. May you continue finishing up Shemoneh Esrei during Kaddish? While the chazan is up to the parts to which you may answer, it makes sense that one must listen and then answer rather than continue davening, because Halacha gives more weight to these main parts of Kaddish than to the Shemoneh Esrei additions. So rules Ishei Yisrael 19:(17) in the name of Rav Chaim Kanievsky. Following this logic, ostensibly the sections of Kaddish and Kedusha that cannot be responded to do not require stopping to listen to (Dirshu 66:11; Halichot Shlomo, Tefilla 8:38). Nevertheless, some say that even though one cannot answer the other parts, he must listen silently to them (Tefilla K’hilchata 12:(246) in the name of Rav Elyashiv). Dirshu (66:11) says they discussed an apparent contradiction in Rav Chaim Kanievsky’s opinion on the matter, and he clarified his opinion – it is better to listen to all of Kaddish or Kedusha, but it is not required.

It is noteworthy to look at a case where you must not respond but should listen quietly to Kaddish and Kedusha ­– during Shemoneh Esrei itself (Shulchan Aruch, Orach Chayim 104:7). The Mishna Berura (104:27) instructs one to listen only to the important parts. Rav Kanievsky there too is cited (Ishei Yisrael 32:(53)) as saying one may stop for longer if he likes. There is room to distinguish between the cases, but that analysis is beyond our present scope.

Since the halacha regarding continuing Elokai Netzor during the less critical parts of Kaddish is inconclusive, I would suggest the following practical guideline. It is fine to continue the few words needed to get to a place (i.e., finishing a phrase of Elokai Netzor and saying Yeh’yu L’ratzon) where you can answer everything. If done wisely, it is not a zilzul in Kaddish but an effort to maximize participation in it. One can argue either way on taking steps backward. On the one hand, one may move about during Kaddish. On the other hand, it is not necessary.

First, remember that your health is paramount and that there is no problem whatsoever doing Havdala without a candle (Shulchan Aruch, Orach Chayim 298:1). If one is able to make the beracha on the candle later that night, that is great (Mishna Berura 298:3).

The mishna (Berachot 51b) states that one can make a beracha on the Havdala candle only when “they benefit from its light.” The gemara (ibid. 53b) cites a machloket on what this means: Rav says it just requires the light to be significant enough that if one were close, he could benefit. Rava requires actual benefit, with the example being that he is able to use it to distinguish between coins. Most Rishonim and the Shulchan Aruch (ibid. 4) rule that one needs to be close enough to benefit from the light.  

On the other hand, according to most authorities, there is no mitzva to actually benefit from the light (see Halacha Berura 298:13). Actually, almost all agree that the beracha is a birkat hashevach (praising Hashem), in this case for creating fire/light, which Adam became aware of on Motzaei Shabbat (see Pesachim 54a). If so, the requirement of how to see the light is to ensure a sufficient trigger for the beracha, as one must see a rainbow or lightening before making a beracha on it.

Therefore, there is logic to say (as Shemirat Shabbat K’hilchata 61:(62) points out) that if the person who is reciting the beracha is properly triggered, those who hear his beracha are appropriately praising Hashem (e.g., by you answering amen from your room). Nevertheless, the Mishna Berura (297:13; 298:13) says that whoever wants to fulfill the halacha of the Havdala candle must be close enough to the light, and I did not find those who disagree. This goes well with the halacha (Shulchan Aruch ibid. 13) that a blind person does not make Borei Me’orei Ha’eish; we do find that he should hear the beracha from someone with sight.

One can suggest various explanations for everyone’s need to be close enough. 1) The mitzva is not limited to the beracha but includes experiencing the light and being reminded of Hashem’s creation, which is capped off with the beracha. This may explain why we make the effort to hold out our hands and look at our fingernails (ibid. 3) and that some do this after the beracha (against the simple halachic logic). 2) One should connect to the beracha as one who is obligated in it, which happens only when he is personally triggered (see Chief Rabbi Yosef’s Birur Halacha 298:(19)).

That being said, even if you cannot make it close to the light, you can salvage the situation significantly. First, if you can light an incandescent lightbulb, some poskim allow using this for Havdala in a case of need (see Piskei Teshuvot 298:10). If so, it would be ideal if you answer amen to the beracha of the mavdil and “attach” the beracha to your incandescent light.

Finally, realize that despite the standard p’sak that one cannot fulfill the mitzva at a distance, hearing the beracha does have some value. First, some poskim say it might be possible you do fulfill the mitzva at a distance, and therefore if you did hear the beracha in this way, you cannot make a beracha later if you gain access (Kaf Hachayim 298:22). The Mishna Berura (297:13) likely agrees, because he says that when one is listening at a distance, he should have in mind not to be yotzei, and make the beracha later when he gains access. Additionally, according to the reasons we gave before, by listening intently to the beracha (you should not answer, as it is likely a hefsek in Havdala), one takes part in the praise of Hashem, just that it is missing either the seeing of the light or taking part in the beracha with an obligation to do so.

It is not possible to answer this crucial question unequivocally. Let us see basic sources and distinctions. We will indeed assume that taking public transportation is a less severe violation of Shabbat than driving, although the extent to which this is true could depend on different factors (eiruv, type of car, etc.).

The most direct source in favor of trying to lighten the level of violation is the gemara in Sota (48a). The gemara says that one type of male/female joint singing is worse than another and that this is notable because of “cancelling this in place of that” (l’v’tulei ha …). Rashi explains that if we can only convince them to stop one, we should stop the more problematic one. Some understand Rashi as not allowing a rabbi to recommend replacing the bigger aveira with the smaller but just choosing on which to focus the criticism. But major poskim understand Rashi more broadly (see Igrot Moshe, Yoreh Deah I:53 and Yabia Omer VI, YD 3 regarding hashgachot that do not prevent “minor” kashrut problems but cover the main halachic issues when without the hashgacha people will eat full-fledged kashrut violations). Rabbeinu Yona (Berachot, 21b in the Rif’s pages) is a Rishon who explicitly allows a rabbi to allow the more lenient violation to prevent the bigger violation.

Another focal gemara is Chagiga 16a. It says that if someone is not able to control his yetzer hara, he should go to a distant place, dress in black, and sin privately rather than desecrate Hashem’s Name in public. Tosafot (ad loc.) offers two explanations whether this is the gemara’s advice to the would-be sinner (lessen the aveira’s damage) or whether it is giving a plan how to avoid the aveira totally.

On the other hand, a gemara )Shabbat 4a) could be grounds for a counterargument – we do not tell someone to do a small aveira in order to save another from a bigger aveira. Very likely, “encouraging” the smaller aveira is itself an aveira (see Yabia Omer ibid.).  

There are different “currents” in Rishonim on whether to apply l’v’tulei ha, and while there could be some machloket, some discrepancies can be explained by distinctions. One is that l’v’tulei ha is more likely when it involves an individual or small group as opposed to a large group (see Sha’arei Chayim (Rotter) 42). Another is that it should not look as if the rabbi is permitting the small aveira, but only that it is better to choose the lesser evil (see Igrot Moshe, OC IV:35). Another major factor is that allowing the smaller violation should not cause people who keep mitzvot to mistakenly sin (see Meishiv Davar 42-43; Igrot Moshe, YD I:53). It is also better if the allowance is temporary, not an ongoing rule (see Rav Asher Sabag in Hama’ayan #246, p. 85). We will leave for now some other possible distinctions.

If you word things correctly, you will not tell him it is permitted to go by bus or that he may use it as a permanent practice, but that he should know that it is preferable. If so, your case comes up on the right side of these distinctions. On the other hand, as poskim point out (see Meishiv Davar ibid.), one should be very careful about if, when, and how to employ l’v’tulei ha. When you are talking about someone whose concepts of Halacha are very limited, to say that some things are important and some are less so, within the same aveira of violating Shabbat, you raise the possibility of confusing him and giving him the wrong impression (e.g., there is no need to do things correctly, as long as it is not “too far off”). You, as the rabbi, can also get into serious communal problems if you think it is a good idea for one and not for another; what often happens is that community members compare notes.

The gemara (Megilla 32a) states that one loses his mitzva if he holds a sefer Torah “naked.” Chazal even instituted that a Torah scroll makes one’s hands tameh so that one should not touch it with his hands (Shabbat 14a). This can be a matter of honor (Levush, Orach Chayim 147:1) or protection for the Torah scroll (Rambam’s commentary to Yadayim 4:6). This creates tension with the halacha (Shulchan Aruch, Orach Chayim 139:11; Mishna Berura ad loc. 35) that one should hold the sefer Torah during the aliya. One answer is that it depends if his hands are considered freshly washed (see Beit Yosef and Bach, OC 147), although most assume that even washed hands may not touch it (Rama, OC 147:1).   

Most poskim (see Mishna Berura 147:2) assume that the prohibition of touching applies only to the klaf, not the etz chaim. Logic indeed dictates that this special treatment is a function of the innate kedusha of a Torah scroll, not the etz chaim, which is only a tashmish kedusha (Taz, OC 147:1). Nevertheless, some assume that as a connected extension of the sefer Torah, one should not touch the etz chaim with bare hands (Bach ibid.). The Magen Avraham (intro. to siman 147) sees in the Rambam’s ruling that the etz chaim makes the hands tameh, an indication that in matters of touching, an etz chaim is like the klaf. Others contend that one cannot extrapolate from the formal halachot of tuma, which equate connected parts of an object, to the halacha of not touching, which logically applies only to the klaf (see Eliya Rabba 147:1). The Maharit (Shut I:136) says that when the Torah is uncovered one should not touch the etz chaim without a separation, because of concern that he will touch the klaf.

Your question implies that you follow the great majority who hold the etz chaim without separation. (Note that the Mishna Berura agrees with the Noda B’yehuda (I, OC 136) that one who wants to be machmir must be discreet to avoid a problem of yohara (“holier than thou”).) So, if we accept the opinion that only the klaf is a problem, your friend seems wrong.

One can argue for your friend’s chumra with the following chakira. Why do we not accept the stringency? If it is because they decided the Taz is fundamentally right, then the whole etz chaim is a tashmish kedusha and can be held directly. However, if the reason is that it is too difficult to expect a fabric between one’s hand and the etz chaim, then arguably it is feasible to ask the oleh to not get his hand closer to the sefer Torah than necessary (see Maharit above). From a technical perspective, when you hold the top of the disc, nothing separates your hands and the klaf (for your friend’s system, the disc does) and depending on the thickness of the roll on that week, the distance could be millimeters. This being said, to create a halachic distinction between parts of the same object, logic is not enough; you need an explicit or at least arguable source. Since we found no source that the disc is different, we reject for your friend’s chumra on halachic grounds.

However, we must note that the great majority of olim to the Torah hold the handle of the etz chaim, not the disc. (Perhaps this is natural because the handle was made for hands, whereas the disc was made to protect the klaf from sliding.) So why would you want to be in the small minority in a manner that fares less well with the spirit of the law? If you are convinced that your practice is an actual family minhag, one can justify it. The Magen Avraham (139:13; see Mishna Berura 139:35) brings a little-known practice – holding the rolled klaf on both sides of the Torah, separated with fabric. This may imply that “the closer to the klaf the better,” provided you do not violate a halacha. Theoretically, your minhag could be based on that approach, in which case it makes sense to preserve it.

This discussion is for those for whom AI is already part of their practical, intellectual, and/or professional lifestyle. What follows is in line with the broad consensus amongst rabbanim in our communities. Hopefully the presentation will clarify somewhat and highlight distinctions and nuances.

A futuristic possibility – Someday, machines might surpass humans in sheer memory, analysis, and application of Halacha (if they do, it will happen later than for most other intellectual endeavors). We must distinguish between halachic information and p’sak halacha. When a halacha is clearly established and a non-expert does not remember facts or know how to “connect clear dots,” the future AI will be trusted. For time immemorial, we do not ask our posek such questions, but ask a more knowledgeable acquaintance. However, when a new question or a unique dilemma including conflicting factors or personal sensitives arises, this requires a p’sak halacha. The process that the Torah describes for deciding such matters (Devarim 17:8-11) involves human talmidei chachamim, which outweighs even a divine omen (Bava Metzia 59b). There is also something to be said for siyata d’shmaya of a yarei shamayim toiling over an answer.

Current AI capabilities – As many know, while AI does certain things in the realm of Torah impressively, its level of reliable scholarship pales in comparison to even a basic-level talmid chacham. AI summarizes straightforward, basic halachic text well. (One AI model retrieved for me my positions on a variety of topics quickly and impressively.) Some of its most impressive feats are plagiarism – summarizing articles by talmidei chachamim without citing them. It can follow Talmudic and halachic logic and notice distinctions. One can get a broad, brilliant answer on a halachic question.

However, it is totally unreliable. It can “quote” non-existent sources. It can “miss” a part of the question and apply an answer in its “grasp” about a similar case; i.e., the answer is wrong for the actual case. It can give an answer based on one source it understood correctly, but fail to realize that most opinions disagree. I compare it to having an absolutely brilliant chavruta who is new to the world of Torah. When it gets something right, it can be breathtaking. However, when that lack of proper background causes it to err, it can say things that sound great but are totally off. My impression is that on “cookie-cutter” clear matters, where there is little complexity and no machloket, it usually gets things right. The chances are higher when one knows how to ask AI in the right way. Moments ago, I asked three AI models the berachot on 7 foods (quite straightforward). They all were accurate about the foods that have one correct answer. The answers for foods upon which there are machlokot differed from model to model, as did the level of accuracy.

Here is my practical summary. A talmid chacham who lacks encyclopedic knowledge, but knows how to check everything before believing anything, can, if he desires, use AI to get to opinions and approaches. He can be aided faster and sometimes more efficiently than by using a Google search to find and read articles or reading through classical sources, which he might find “the old way” or with the help of Bar Ilan Responsa, Otzar Hachochma, etc. It serves more like a halachic anthology sefer with an “automatic index” when you don’t look up the sources cited in footnotes. The researcher must avoid the danger of falling into the horrible habit of believing too much, which already exists regarding some anthology sefarim; it certainly exists for AI. To quote one AI model’s disclaimer: “XXX is AI and can make mistakes. Please double-check cited sources.”

For those who are not talmidei chachamim, using AI to get Torah information is usually highly irresponsible. (This is true for non-experts regarding other intellectual or professional fields.)

The gemara (Bava Metzia 101b) does say that the obligation of putting up mezuzot on rental property is on the renter, implying not on the landlord (see also Avoda Zara 21a). While this is practical for a lengthy rental, a tzimmer owner could not expect that vacationers will bring mezuzot with them. Actually, though, the vacationers do not need them.  True, in Eretz Yisrael, a renter is required to affix mezuzot right away, as opposed to in chutz la’aretz, where there is a 30-day “grace” period (Menachot 44a; Shulchan Aruch, Yoreh Deah 286:22). However, even in Eretz Yisrael, one who stays in a pundak (an inn for travelers – Rashi ad loc.) is exempt from mezuza (ibid.). This applies to hotels and tzimmers as well (Chovat Hadar 3:5), at least for 30 days (see S’dei Chemed vol. V, p. 63; Mishneh Halachot IV:134).

Then, the question becomes – if your guests are exempt, does that mean you are obligated? This depends on the rationale of the gemara (Bava Metzia 101a) that mezuza is the obligation of the dar (the renter who is living there). Some posit that if one owns a house but does not live in it (i.e., the landlord) he is fundamentally exempt from mezuza (Tosafot, Avoda Zara 21a). If so, if you never use the tzimmer as part of your “living quarters,” you should not be obligated. On the other hand, Rav Yehonatan (cited in Shita Mekubetzet, Bava Metzia 101b) posits that according to Torah law, the landlord is obligated in mezuza, but they obligated the renter because he is the one who benefits from the mezuza’s protection. According to this latter approach, if the guests are not obligated during their insufficiently significant stint, the owner would be obligated.

Even if a permanent landlord is not obligated on any level in attaching mezuzot, you might be obligated. One possibility is that the fact that you are dealing with the tzimmer commercially, to make money, on an ongoing basis rather than on a one-time basis, makes it considered a use of the money maker (see Torat Hamezuzah p. 104). This is enhanced if, as proprietor, you often have to go in and take care of the tzimmer (see Igrot Moshe, Yoreh Deah II, 141). Also, the Shevet Halevi (II:156) says that even if hospital patients do not require a mezuza on their room (due to the nature of the stay), a Jewish hospital would require mezuzot on all its doors. This is not only because the Jewish staff frequent the rooms, but also because of the Jewish ownership. (He does not discuss whether they are affixed with a  beracha.)

The approach that the owner does not need to live there like a home depends on the question of mezuzot for the workplace (which we discussed in Living the Halachic Process, I:G-4). The Rambam (Mezuza 6:9, accepted by the Shulchan Aruch, YD 286:11) says that a store in a marketplace does not require mezuzot seems to imply that mezuza requires domestic living. However, some attribute the Rambam’s exemption to other factors – it is used only in the daytime; the market was only on certain days. Still, most poskim suggest not making a beracha on attaching the mezuza to a commercial space due to doubt about the requirement (see LTHP ibid.).

The simplest advice is to affix the mezuzot without a beracha. If you want to find a way to make a beracha appropriate, you can use the tzimmer for personal needs either before turning it commercial or even afterwards, if you do so from time to time. This includes having close family and friends being semi-frequent occupants, as many consider the living use of such people like your own (see Torat Hamezuza ibid.). Note common practice is that one who moves into a house that has a room set aside as a guest room affixes a mezuza on it without a beracha, even if the guests are not constant!

The gemara (Ta’anit 30a) says that all mitzvot of aveilut during shiva apply to us all on Tisha B’av. As we know (although the sources on this are complicated – see Beit Yosef, Yoreh Deah 387), an avel does not sit on a regular chair, and therefore the same should be true on Tisha B’av. However, when the Shulchan Aruch and Rama (Orach Chayim 559:3) codify this practice for Tisha B’av, they say that it is only for part of the day.

Some explain that the time limitation stems from the fact that sitting low on Tisha B’av is apparently a chumra, as there are no explicit Talmudic sources about sitting low, and so we are lenient (see Mishbetzot Zahav 559:4). The Taz (OC 559:4) says that it is a full-fledged halacha, but that the gemara, by presenting a broad rule that equates between shiva and Tisha B’av but leaves sitting low off the list of examples, hints at a compromise regarding its duration.

The Bach (OC 559) argues that one’s sitting on Tisha B’av should not be derived from aveilut because the comparison is only for negative commandments. The Taz (ibid.) responds that sitting low is indeed a negative commandment (not to sit regularly), not a positive one (to sit low). He therefore posits that standing is fine, because only improper sitting is forbidden. According to him, standing or lying down is neutral. Even if there is a positive mitzva to sit low, it is hard to imagine one being required to remain seated the whole time. Rather, there should be a significant amount of sitting low, and the whole time this applies, it is forbidden to sit normally.

There is a lack of clarity as to how low this should be. Rishonim, including the Ramban (Torat Ha’adam, Aveilut 63) and the Tur (OC 559) speak of sitting on the ground, and this has a basis in the gemara and even Tanach (see Iyov 2:13). However, it is permitted (and perhaps preferred – see Nitei Gavriel, Bein Hametzarim 2) to put something between him and the ground (Mishna Berura 559:11). When it is difficult to sit that low, one can sit on a low chair/bench (ibid.). While many assume the cutoff point is three tefachim, others say it is enough that it is noticeably lower than normal (see opinions in Dirshu 559:13). Certainly, whatever is acceptable during shiva is permitted on Tisha B’av.

Regarding your discomfort, on the one hand, the practice is supposed to make it uncomfortable. On the other hand, it is not intended to cause someone qualitatively more pain than the average person. If a low chair will work for you, it behooves you to obtain one, and if you decide not to bother and it is not damaging to you, it was your decision to handle the discomfort and/or stand part of the time. Since even by aveilut it is accepted that those for whom it is truly difficult may sit on a normal chair (Aruch Hashulchan, YD 387:3), if it becomes truly difficult you may sit as you need to. In summary, the order would be: using a low chair, certainly if it is less than three tefachim; standing as much as you need; and finally, sitting on a regular chair when it is necessary.

Regarding the timing, while there are sources about staying seated low until finishing Shacharit/Kinnot is over (see complex language of the Rama, OC 559:3). Important sources, including the Magen Avraham (559:3) and Pri Megadim (559, MZ 4) mention chatzot specifically. Nitei Gavriel (ibid. 68:13) posits that the proper position for Kinnot is sitting, even after chatzot, but his support for this claim is weak.  So, while those who are machmir while Kinnot continue have basis, even one who is often machmir need not do so if it is difficult.

A mishna (Ta’anit 26b) forbids haircutting during shavua shechal bo Tisha B’av. Ashkenazi minhag extends this to the entire Three Weeks (Rama, Orach Chayim 551:4).

For your son, there are two grounds to consider for leniency. One is that if he gets it before his halachic birthday, he is then a katan. Although we do not normally allow haircutting for ketanim (Shulchan Aruch, OC 551:14), the Mishna Berura (ad loc. 82) cites without a clear preference two opinions if this applies during the Three Weeks where the whole prohibition is just a disputed minhag. It seems that people are usually machmir on this.

Your main question is probably whether the simcha of a bar mitzva celebration permits haircuts/shaving. The Rama (OC 551:1) allows the principals to a brit mila to wear Shabbat clothes to the brit right up until Tisha B’av. Acharonim debate whether or not this leniency applies to haircutting as well, which is more stringent than wearing nice clothes (see Eliya Rabba 551:28; Sha’arei Teshuva 551:1). As we have seen, the Talmudic prohibition is only on shavua shechal bo, so that there is extra room for leniency earlier in the Nine Days, and certainly during the Three Weeks.

How does a bar mitzva boy’s halachic level of simcha compare to the principals of a brit mila. The Yam Shel Shlomo (Bava Kama 7:37) proves from the following gemara that we can call a bar mitzva a mitzva celebration. The gemara (Kiddushun 31a) tells of the blind sage, Rav Yosef. Rav Yosef said that if he would be convinced that the blind are obligated in mitzvot, he would make a celebration because one who is commanded in mitzvot receives more reward for their fulfillment. If a celebration is in place for one finding out that he has always been obligated, it is certainly appropriate (he does not call it an obligation) when a bar mitzva becomes obligated in the mitzvot. The Magen Avraham (225:4) and Mishna Berura (225:6) accept this Yam Shel Shlomo. While the bar mitzva seuda is not mentioned in the Shulchan Aruch/Rama, it is at least as important as a siyum, where we allow eating meat and drinking wine in the Nine Days (Rama, OC 551:10). On the other hand, we do not find people making a siyum getting haircuts in the Nine Days. Therefore, poskim are not confident about allowing haircuts for a bar mitzva boy (see Nitei Gavriel, Bein Hametzarim 20:6; Mishneh Halachot (VI:45) regarding a bar mitzva during sefira, which is a somewhat weaker level of aveilut than the Three Weeks).

In your case, there is also little practical need for a Three Week haircut, as it is generally assumed that a male’s hair looks its best several days after the haircut. Therefore, we would recommend doing your son’s haircut before the Three Weeks, but if you forgot to do so and he does not look his best, we have seen enough room for leniency for a bar mitzva boy during the Three Weeks (see Nitei Gavriel ibid.).

Regarding your shaving, fundamentally, when haircuts are forbidden, that includes shaving (Shulchan Aruch, Yoreh Deah 389:1). Rav Soloveitchik is among those who say that those for whom nowadays shaving is no longer done periodically but is daily upkeep, may shave during the Three Weeks. Unless you have a significant beard, shaving before the Three Weeks will not be of much help. We can acknowledge, that you too are likely somewhat of a principal to the bar mitzva (see language of Magen Avraham ibid. and notice that you also recite “Baruch shepetarani …” (Rama, OC 225:2). Rav Mordechai Willig (Am Mordechai, Berachot 29) explains that the father is celebrating the completion of the fulfillment of the formal mitzva to educate his son. Therefore, although you imply you do not shave during the Three Weeks, if you rely on the leniency for a moderately important need (e.g., Shabbat, an important business meeting), it is appropriate to do so for the bar mitzva as well.