Observation: The Yerushalmi teaches that one must do something new to it (i.e. lift up the Sechach and place it down). Chevraya say he must do this to one Tefach of the Sechach. Rebbi Yosi says if he does this to even a minute amount it is enough, however he must do this to a minute amount across the entire Sukah (a few inches across the length or width of the Sukah).

Observation (cont.): Afterwards, the Yerushalmi there sys that "old Matzah" is the subject of an argument between Beis Shamai and Beis Hillel (just as they argue in our Mishnah). Rebbi says that everyone agrees regarding Matzah that since he did not make it with intent to use it for Pesach it is clear that he was not careful to make it according to law.

Explanation: Even according to Beis Hillel there is a reason to make it with intent for Sukos, as this avoids having to do something new to it (as stated in the previous Tosfos).

Explanation (cont.): Even if the only difference whether one does so or not is according to Beis Shamai, the Tana must explain the reasoning behind their argument. One cannot ask why the Mishnah is teaching us the reason of Beis Shamai (when we never rule like them, and do not do so in this case either) unless Tanaim are arguing regarding what Beis Shamai holds and this is not relative at all to Beis Hillel's position on the matter, as in the Gemara in Shabbos (135a), Yevamos (28a, the Bach takes the word "Kashya" out of Tosfos), and Beitzah (7b). We explained all of these Gemaros in their proper place.

Explanation: This implies that this is a Torah prohibition and a regular derivation, as the Gemara asks, "Is this Pasuk indeed required for this teaching?" (This would not be said if it was a mere Asmachta.)

Question: This is difficult, as in Shabbos (45a) there is an implication that this is a Rabbinic law. The Gemara there quotes a proof that Rebbi Shimon holds regarding a candle that since it is Muktzah for the Mitzvah (of Shabbos candles) it is Muktzah for its prohibition (against putting out its flame).

Question (cont.): The proof is from the Beraisa that states that one cannot take wood from a Sukah on Yom Tov. Rebbi Shimon permits this. They agree that one cannot take wood from a Sukah on Sukos. In Beitzah (30b), the Gemara quotes our derivation, and even so the implication there at the end of the Gemara is that it is only forbidden due to Muktzah, as we say that the wood of the Sukah that became holy is set aside for seven days (to only be used as part of a Sukah).

Opinion #1: The Torah prohibition is when it is still standing as a Sukah. It is forbidden at this time to take wood from the Sukah. However, after it falls down and its Mitzvah is nullified, it is only forbidden to take wood from it according to Rabbinic law.

Implied Question: The Gemara asks in Beitzah, does a condition help? (Why does the Gemara quote the Torah derivation and ask such a question when it is a Rabbinic law, as the Gemara there is referring to a Sukah that fell down?)

Answer: The Gemara is saying that since a condition does not help when it is standing, it should also not help after it fell down, as since the Sukah was Muktzah during Bein Hashemashos it should be Muktzah for the entire seven days of Sukos! The Gemara answers that the second part is referring to a regular Sukah (not built for the Mitzvah). The Gemara then asks that a condition does help for Sukah decorations. The Gemara answers that this is only when he says, "I am not staying away from them all of Bein Hashemashos" as this means they were not set aside for the Mitzvah.

Answer (cont.): They are unlike wood of a Sukah which is part of the main aspect of the Mitzvah of Sukah (i.e the body of the Sukah), and a person therefore separates himself from them and would transgress breaking an Ohel if he took from the wood.

Observation: Even though the Gemara knew this reason before, it is normal for the Gemara to explain itself through asking questions and giving answers.

Opinion #2: Rabeinu Tam explains that the wood needed for a minimum size of the Sukah has holiness and is forbidden to be tampered with according to Torah law. However, any wood more than the minimum amount is only forbidden to be used according to Rabbinic law.

Implied Question: The Gemara asks, "Does a condition help?" (See d).

Answer: This is because just as a condition does not help for something that is prohibited according to Torah law, similarly it does not help for something that is forbidden according to Rabbinic law. The Tana does not differentiate between wood that is needed for the (minimum size of the) Sukah and wood that is not needed. (Tosfos ha'Rosh says that the wood that is forbidden is the Sechach, not the walls. However, Tosfos in Beitzah and the Rambam argue that it is referring to the walls as well, see the Maharsha on our Tosfos.)

Question: Regarding the Gemara in Beitzah there is a difficulty from the Gemara in Shabbos (22a) that implies that Sukah decorations are forbidden due to the Mitzvah being denigrated, not because of Muktzah.

Answer: We explained this there.

Explanation: Rebbi Yehudah ben Beseirah holds that if not for Chagigah we would establish this Pasuk as teaching that a Sukah must be made with intent that it is for Sukos.

Question: This is difficult. We should derive that this is invalid because it is a Mitzvah done through a sin! For this very reason we say later (29b) that a stolen Esrog cannot be used on Yom Tov Sheini!

Question: In that Gemara itself there is a difficulty! The Gemara says that it is understandable that it is invalid on the first day of Yom Tov, as the Pasuk states, "for you" implying that it must be yours. However, on Yom Tov Sheini, why is it invalid? The Gemara answers that this is because it is a Mitzvah done through a sin. If this is so, why do we need the Pasuk to state "for you?"

Answer: However, there it is possible to answer that we need "for you" to exclude a borrowed Lulav (on the first day). However, regarding Sukah we cannot answer this according to the Rabbanan who say later (27b) that a person can fulfill his obligation in his friend's Sukah (even on the first night). We derive this from the Pasuk, "All citizens of Israel should sit in Sukos," which teaches us that all Yisrael are fit to sit in one Sukah.

Answer: The reason that a Mitzvah done through a sin is invalid is a Rabbinic reason (according to Torah law one would indeed fulfill the Mitzvah).

Question: However, there is a difficulty from the Gemara in Gitin (55a) regarding a stolen Chatas that the public does not realize is stolen (and it is brought as a public Chatas). Ula says that whether it was known beforehand or not that it was a stolen sacrifice, it does not atone. Why? The original owner having despaired of ever getting his animal back is not enough to cause the public to acquire it. Yet we know that Ula holds that if the original owner despairs of getting back the item, it is enough to allow someone else to acquire the item according to Ula, as he states regarding the case of skins of an owner and different thieves!

Question (cont.): Rabeinu Tam answers the contradiction in Ula by saying that the Olah is invalid because it is a Mitzvah done through a sin (and is not related to whether the owner despairs or not). (This indicates that the law that a Mitzvah done through a sin is invalid is a Torah law!)

Answer #1: However, this answer (of Rabeinu Tam) cannot be true, as the Gemara in Gitin explicitly says that Ula's reason is that despairing does not allow someone else to acquire the animal (and therefore there is no question from this contradiction in Ula to saying that a Mitzvah done through a sin is a Rabbinic issue).

Answer #2: Additionally, in Bava Kama (67b) Rava explicitly teaches that despair does not allow someone else to acquire since the Pasuk says, "his sacrifice - and not one that is stolen."

Observation: It seems that the Gemara in Bava Kama (ibid.) is not referring to despair alone, rather despair and a change of the item's name. This is as stated in Bava Kama (66b) that it was originally called a Mashcha and now it is called an Abarza.

Implied Question: This is despite the fact that a sacrifice also goes through a name change, as the Gemara says in Bava Kama (67b) that it used to be called Chulin and now it is called Kodesh. (Why isn't this sufficient to have the animal change owners, enabling the stolen public sacrifice to be valid?)

Answer: Even so, this is excluded from the Pasuk, "his sacrifice," since before it was Hekdesh it was not his. Even though it becomes Hekdesh due to the change of its name, it is not fit to offer it as a sacrifice since it must be able to be called "his sacrifice" when he is dedicating it to be a sacrifice.

Explanation #1: This is because the tree is attached to the ground and Sechach must be detached, similar to the residue from silos and grape harvests. If the Sukah that is underneath the tree has Sechach that provides more shade than sun, it does not make sense that it should become invalid just because it is joined by Sechach that is invalid. If you would take away the invalid Sechach it would still have more shade than sun! Rather, it is invalid if the Sukah does not have Sechach that provides more shade than sun unless it uses the (invalid) shade of the tree.

Implied Question: The Gemara does not answer that the case is when there is more shade than sun without the invalid Sechach. (If our explanation is correct, why isn't this used as an answer given by the Gemara?)

Answer: If so, what is the novelty of this case? Even when the Gemara answers that the case is when the tree branches and Sechach are mixed together, the Gemara still asks about the novelty of the case.

Proof #1: This is clearly true (that once a Sukah has enough valid Sechach we do not care if there is invalid Sechach as well above it or next to it), as regarding a person who covers his Sukah with metal spits or bed boards (in order to use these as support to lay his Sechach on top of them) we say that the Sukah is valid (15a) if there is space between these spits or board (to place kosher Sechach) equivalent to the spit or board.

Proof (cont.): This is despite the fact that mixing the Sechach and spits should not help to cause Bitul b'Rov, since these are clearly two different items that do not form a mixture as they remain separate entities. We do not say that it should be invalid because one is combining invalid and valid Sechach, as if you were to take away the invalid Sechach there would be enough valid Sechach for it to be a kosher Sukah.

Proof #2: Additionally, we say earlier (4b) that if the Sukah was higher than twenty cubits and some branches of the Sechach were hanging into the area less than twenty cubits from the ground, if these branches provide more shade than sun for the entire Sukah the Sukah is valid.

Implied Question: We say later that (if there is a Sukah on top of another Sukah) the bottom Sukah is valid and the top one is invalid in a case where the bottom one has Sechach that provides more shade than sun and the top one provides more sun than shade. Both of these Sukos are under twenty cubits. This implies that if the top Sukah was higher than twenty cubits the bottom one would also be invalid, since he is combining invalid Sechach with valid Sechach! (This is unlike our explanation that there is no problem in doing so as long as the Sukah has enough valid Sechach that provides more shade than sun!)

Answer: The case there is when the bottom Sukah does not have shade than sun without combining its Sechach with the Sechach of the top Sukah.

Observation: Similarly, it would have been possible to say that both Sukos should be invalid if the top Sukah was higher than twenty cubits. However, the Gemara found this case to be valid without needing to use that case.

Question: Since the bottom Sukah does not have more shade than sun without the Sechach of the top Sukah, why is it valid?

Question (cont.): The Gemara later (22a) says that a Sukah ha'Meduvleles is valid. Shmuel explains in the Gemara that the case is where one reed is above and one is below. Abaye says that this is only in a case where there is not three Tefachim between each reed. However, if there is three Tefachim between each reed, it is invalid.

Answer: Rava says there that even if there are three Tefachim between the reeds, if the top reed is a Tefach tall we view it as if it is lowered next to the other reed.

Explanation #2: Rabeinu Tam explains that Sechach that is above twenty cubits is not even considered invalid Sechach, since it is only a problem due to it being placed in a high area (and it is not intrinsically invalid Sechach).

Proof #1: This is because Rabeinu Tam has a difficulty with the Gemara's statement that we need to say the case where the bottom Sukah is valid and the top Sukah is valid. One might think we should say the invalid Sechach should combine with the valid Sechach to make the bottom Sukah invalid.

Proof #1 (cont.): Rashi gave a forced explanation that even though the top Sukah is within twenty cubits, one might think that we should decree that the bottom Sukah is invalid because sometimes the top Sukah will be higher than twenty cubits, and people will not realize that the bottom Sukah is combining its valid Sechach with the invalid Sechach of the top Sukah. When they see the top Sukah has more sun than shade, they will think that its Sechach is insignificant and that it does not invalidate the bottom Sukah (even though it does). This is why we must teach that we do not make such a decree when the top Sukah is within twenty cubits lest a person confuse it with a case where the top Sukah is above twenty cubits. This is a forced explanation.

Proof #2: Additionally, for this same reason the Gemara could have said the case where both are valid needed to be taught!

Text: Rabeinu Tam understands that the proper text should read that the bottom Sukah is valid and the top Sukah is invalid. What is the case? The case is where the top Sukah has more sun than shade and the bottom Sukah has more shade than sun. The bottom Sukah is under twenty cubits, meaning that we do not care about the top Sukah at all. Even if it is higher than twenty cubits it will not cause the bottom Sukah to be invalid!

Text (cont.): This is what the Gemara means when it says that one might think that we should combine the invalid Sechach with the valid Sechach. It means that one might think that the Sechach of the top Sukah should be considered invalid if it is over twenty cubits high. This case is therefore taught to teach that this is incorrect (and it is not considered invalid Sechach).

Proof #3: The Gemara in the beginning of Eruvin (3a) slightly implies that Rabeinu Tam is correct. It says regarding a case where some of the Sechach is under twenty cubits and some is above that even if you were to take away that Sechach the Sukah would have less shade than sun etc. This implies that it is valid because it is currently providing more shade than sun.

Implied Question: However, regarding the case of some branches being lower than twenty cubits we explained earlier that even if the Sechach above twenty is considered invalid Sechach the Sukah is valid, since the case is where the Sechach that is less than twenty can cause the entire Sukah to have more shade than sun.

Implied Question (cont.): When we say that if you take away the Sechach it will provide more sun than shade, this means that the Sechach that is within twenty cubits (which can by itself provide more shade than sun) will not stay on top of the Sukah because it is weak and the wind can easily scatter it or make it fall down (without the branches that are above twenty cubits). (If this is correct, there is no support to Rabeinu Tam's opinion from this Gemara in Eruvin.)

Explanation: Even the opinion that we primarily use the Mikra admits that the Mesores is not written for nothing, as I explained earlier (6b, DH "v'Rebbi Shimon").

Explanation: I already explained this earlier.