Shalom and thank you for submitting your question.

The Gemara and Shulchan Aruch rule that on Shemini Atzeres in Chutz la'Aretz, one must sit in the Sukah but he does not recite a Berachah of Leshev ba'Sukah. This seemingly implies that on the eighth day one should continue sitting in the Sukah just as he has been doing for the past seven days, the only difference being that he does not recite a Berachah. This indeed was the custom of the Vilna Gaon, who ate and slept in the Sukah on the eighth day.

However, other customs do exist. Although many Halachic authorities reject the other customs, it is clear from those Halachic authorities that the other customs are not new practices. Let us discuss a few of the customs, and some of the arguments suggested to defend them.

1. The Mishnah Berurah states that most people do not sleep in the Sukah on Shemini Atzeres.

2. The Tur mentions a custom to eat in the Sukah only during the day but not at night on Shemini Atzeres. The Beis Yosef explains that eating the evening meal in the Sukah on Shemini Atzeres, as though it is still Sukos, and reciting Shehecheyanu at that meal for the holiday of Shemini Atzeres, is a contradiction. Therefore, one should not eat in the Sukah at night. (The Tur rejects this argument.)

3. A common custom is to sit in the Sukah only when saying Kidush during the day. The source for this is very unclear. Some explain that when one sits in the Sukah on Shemini Atzeres, he must do so in a way such that it is not obvious that he is trying to fulfill a Mitzvah. Otherwise he might be transgressing the Lav of Bal Tosif. Hence, in countries where the climate is very chilly during this season of the year, one cannot pretend that he is sitting there for the sake of convenience. It is obvious that he is sitting there for the sake of the Mitzvah, in which case the problem of Bal Tosif surfaces. Although the Gemara does rule that one must sit in the Sukh on Shemini Atzeres, the ruling was only meant for the people of Bavel, according to this opinion, since the climate there was fairly comfortable during this time of the year, and it would not be uncommon for a person to eat his meal outdoors even if he was not doing so to fulfill the Mitzvah.

Y. Landy

This is an excellent question.

1. What you say is in fact stated in Shiltei Giborim on the Rif Rosh Hashanah 9b (in the pages of the Rif), #3, that someone who adds on to the Mitzvos does not transgress Bal Tosif unless he intends to add on to the Mitzvos. Therefore, we sit in the Sukah on the eighth day and blow Shofar on the second day of Rosh Hashanah, and we eat Matzah on the second night of Pesach with a Berachah. Since we do these things only because of the doubt, we do not intend to add to the Mitzvah and therefore do not transgress Bal Tosif.

2. We must understand why the Mordechai (Sukah #772, which is a source for the practice to eat in the Sukah on Shemini Atzeres but not to sleep there) writes in the name of the Ra'avyah that since one does not recite a Beracha on eating on the eighth day (even though one recited a Berachah all seven days), this serves as a "Heker" which indicates that it is not considered as though one is adding on to the Mitzvah. In contrast, it is forbidden to sleep in the Sukah because it looks as if one is adding to the Mitzvah (because one never says a Berachah on sleeping in the Sukah).

3. To resolve this apparent contradiction between the Shiltei Giborim and the Ra'avyah, I would first like to point out that the Ra'avyah does not actually say that someone who sleeps in a Sukah on Shemini Atzeres transgresses Bal Tosif. Rather, he writes that it looks as if he is adding to the Mitzvah. The Ra'avyah agrees that he is not really adding on to the Mitzvah since he has no intention to do so.

4. I suggest also that the Ra'avyah also makes use of the reasoning cited by the Mishnah Berurah (OC 668:6) to explain the practice of those who do not sleep in the Sukah on Shemini Atzeres. He writes that people sometimes eat in the Sukah even when there is no Mitzvah involved in doing so (merely because it is pleasant to eat in a Sukah), while, in contrast, when one sleeps in a Sukah it is noticeable that one is doing so only because of the Mitzvah. Therefore, the Ra'avyah maintains that when someone sleeps in the Sukah, it appears to others as if he is adding to the Mitzvah of seven days, even though the person himself knows that he is not.

5. On Pesach, we eat Matzah also because we are hungry or because it is tasty, and we also might blow the Shofar on Rosh Hashana because we like the sound of it. However it is unusual for someone to sleep in the Sukah merely for enjoyment. Therefore, it looks as if one is doing so merely for the Mitzvah and this is similar to adding on to the Mitzvah.

Dovid Bloom

I found that your question is, in effect, asked by Rav Elyashiv zt'l in his He'oros to Maseches Sukah 47a (page 222, DH v'Hikshu).

1. Rav Elyashiv says that the Acharonim, the later commentaries, asked how could it be that here it is said that if someone sleeps in the Sukah on Shemini Atzeres, this looks as if he is adding on to the Mitzvah? (Note that Rav Elyashiv does not say that this is full-scale Bal Tosif, but rather merely that it appears like Bal Tosif. -DB) What is the difference between this and all other Mitzvos, such as blowing the Shofar on the second day of Rosh Hashanah, where we do not say that it appears as though one is adding to the Mitzvah?

2. Rav Elyashiv answers that, in general, all Mitzvos that we do on Yom Tov Sheni are not considered as adding to the Mitzvos, since we do them only because of doubt, or because of the Minhag. However, Shemini Atzeres is different, because in this case our behavior is self-contradictory. If it is still Sukos (which is suggested by the fact that we are sleeping in the Sukah), then it cannot be Shemini Atzeres. It follows that by sleeping in the Sukah on Shemini Atzeres we are insulting Shemini Atzeres by behaving on it in the way that we behave on Sukos. If we do nothing to indicate that tonight's sleeping is different from the sleeping of the previous seven nights (in the same way that when we eat in the Sukah we indicate this by not making a Berachah, even though we recited a Berachah for the last seven days), then we give the appearance that we are adding to the Mitzvah by suggesting that on Shemini Atzeres one must also sleep in the Sukah.

According to this, the "Mosif" -- the addition being discussed here -- constitutes adding on to Shemini Atzeres (by adding the Mitzvah of sleeping in the Sukah to the Mitzvos of Shemini Atzeres), but not adding a Mitzvah to the first seven days.

Kol Tuv,

Dovid Bloom

I found (b'Siyata d'Shemaya) that the answer I suggested in the first reply, point 4), appears to be backed by major authorities.

1) One of the Rishonim, the Agudah on Maseches Sukah (#44), writes that according to the Ra'avyah, when one sits in the Sukah this does not appear to constitute an additon to the Mitzvah, because people sometimes enjoy eating in the Sukah regardless of the Mitvah.

2) The Levush (#668) writes something similar when he states that people do not usually sleep in a Sukah if not for the purpose of fulfiling the Mitzvah, so if he sleeps in the Sukah on Shemini Atzeres this looks as if he is adding to the Mitzvah.

3) We observe from the above two Poskim that they add something to what is written by the Mordechai (#772). The Mordechai mentions only that eating in the Sukah on Shemini Atzeres is not considered as an addition, because one does not recite a blessing. The Agudah adds the fact that sometimes people like to eat in the Sukah regardless of the Mitzvah. Similarly, the Levush adds the reasoning that nobody sleeps in a Sukah if not for the Mitzvah.

4) This supports what I wrote in the earlier reply (in #4), that it is not sufficient merely to have the reasoning of the Mordechai that if one does not recite a blessing, then this proves that one is not adding to the Mitzvah; rather, we also require the important logic that people eat in their Sukah merely for enjoyment, while one sleeps in the Sukah only in order to fulfill the Mitzvah.

Dovid Bloom

Yasher Ko'ach!

1) The Mordechai (Megilah #775) to which you refer is in fact cited by the Sedeh Chemed, volume 1, page 415 (in the entry on Bal Tosif) in the name of the Maharsham (the Rav of Barzan). This is from the emendations of the Maharsham to Orchos Chaim 31 (Spinka), and is referring to the Magen Avraham, Orach Chaim 31:2, who writes that if one lays Tefilin on Chol ha'Mo'ed one does not transgress Bal Tosif because one is not intending to add on to the Mitzvah. On this the Maharsham comments that the concept stated by the Magen Avraham is not accepted by the above Mordechai. This is the same as what you wrote.

2) However, I could not understand the Maharsham, because the Din of the Mordechai is different. The Mordechai writes that 15 Adar may also be considered "Zimnei" -- a proper time for reading the Megilah -- even for a person who lives in a non-walled city. The reason is that if people from a walled city are in a non-walled city on the 15th, the non-walled inhabitant may read the Megilah for them (and be Motzei them). Therefore, both the 14th and the 15th are considered Zimnei even in the non-walled city. It follows, according to the opinion in Eruvin (96a) that at the time of the Mitzvah one transgresses Bal Tosif even without intent to do so, that on the 15th one always transgresses Bal Tosif. This is not similar to the second day of Yom Tov, because in that case a doubt exists, while, in contrast, on the 15th of Adar no doubt exists because it is certainly the right day in a walled city, and therefore it is also the right day even in a non-walled city because he could be Motzei a walled inhabitant on the 15th.

3) The above is apparent in the words of the Mordechai. Concerning the person who read on the 15th, he writes that he transgresses Bal Tosif, which suggests that this is d'Oraisa. In contrast, the Mordechai in Megilah (#772) writes that someone who sleeps in the Sukah on Shemini Atzeres merely looks as if he is adding to the Mitzvah, which suggests that this is only d'Rabanan. The difference is that in Sukah it is only a Safek, while on Purim both days are certainly Purim with no doubt.

4) According to the above, one does not have to say that there is any opinion that one transgresses Bal Tosif even for a Safek. See also aforementioned Sedeh Chemed, who is surprised that the Maharsham wrote that there is a dispute on this point.

Kol Tuv,

Dovid Bloom