1)

(a)We query Abaye according to Rav (who applies the principle of 'Gud Achis' even if it is to enclose a space for which it was not originally made) from our Mishnah, which invalidates a Sukah in the Chatzer, when it is surrounded by a covered passageway that is more than four Amos wide. To reconcile Abaye with the Mishnah, Rava establishes it - when he placed the Sechach in between the two Achsadros (instead of on top of them), leaving nothing visible on which to say 'Pi Tikrah Yored v'Sosem'.

(b)We just cited the version of Abaye and Rava's Machlokes that was learned in Sura. According to the version learned in Pumbedisa - both Abaye and Rava rule Pasul in a case where one placed Sechach on an Achsadra which has no posts ...

(c)... and they argue over a case where there are posts.

(d)The basis of their Machlokes is - whether we apply 'Lavud' in a case where the posts are not specifically made to surround the space which they do surround (like they argue in the first Lashon regarding 'Gud Achis').

(e)And we rule - like Rava according to Rav in the first Lashon.

2)

(a)In view of the previous ruling, Rav Ashi was surprised to find Rav Kahana (the second) - placing Sechach on an Achsadra that did not have posts.

(b)Rav Ashi saw - only a Sukah that had two adjacent walls, and no third wall of a Tefach plus could be seen (so he thought that Rav Kahana wanted to form the third wall of the Sukah through 'Pi Tikrah Yored v'Sosem').

(c)Rav Kahana pointed to Rava however - that there was a third wall consisting of one Tefach plus, that was level with Sukah on the inside but which jutted out on the outside, where it could be clearly seen to be a wall; alternatively, it jutted out in such a way that it could be seen by people standing inside the Sukah, (but not by people standing outside (and Rav Ashi was looking at the Sukah from the outside). Such a wall is in fact Kasher regarding Sukah, and we learn it from ...

(d)... the Din of Lechi (an upright post) - regarding which both of these cases are valid (as we learned in Eruvin) and permit carrying in the Mavoy. (See Tosfos DH 'Achvei Lei', and Rosh Siman 34)

3)

(a)The Beraisa rules - that 'Pesel ha'Yotzei min ha'Sukah' is considered a Kasher Sukah.

(b)Accordin to Ula, 'Pesel ha'Yotzei min ha'Sukah' means - Sechach that protrudes behind the third middle wall of the Sukah.

(c)To answer the question that a Sukah requires ...

1. ... three Kasher walls, we answer - that it does indeed have three independent walls.

4)

(a)Rabah and Rav Yosef establish 'Pesel ha'Yotzei min ha'Sukah' by Sechach that extends from inside the Sukah - but when only one of the walls extends together with the Sechach (i.e. that section of Sukah only has one wall).

(b)The Beraisa is coming to teach us - that it is Kasher, even though it does not have a Hechsher Sukah on its own, it is nevertheless Kasher ...

(c)... because it is similar to the Din of two walls of seven by seven Tefachim where the third wall is a Tefach.

(d)Rabah bar bar Chanah quoting Rebbi Yochanan, establishes it by a Sukah where most of its Sechach casts more shade than sunshine - but a small section does not. The Tana is teaching us that even that small section (which is called 'Pesel') is Kasher, despite the fact that it has 'gone out of the (Hechsher) Sukah'.

5)

(a)Rebbi Hoshaya explains 'Pesel ha'Yotzei min ha'Sukah' by Pasul Sechach - meaning Pasul Sechach of less than three Tefachim in a small Sukah, which is Kasher, even though it has 'left the (laws of) Sukah'.

(b)Rav Hoshaya queries him from a small Sukah with a space of less than three Tefachim in a small Sukah - which does also not invalidate the Sukah. So bearing in mind that space is more stringent that Pasul Sechach, the Tana should not have needed to mention the Din in the case of the latter.

(c)Rebbi Aba answers - that the Tana is coming to teach us that one is even permitted to sleep underneath the Pasul Sechach (which one is not allowed to do underneath the space).

(d)We still query Rebbi Hoshaya however - in that seeing as Sechach Pasul is in itself Pasul, how can it possibly combine to make a Sukah Kasher?

6)

(a)In answer to the Kashya, Rebbi Yitzchak ben Elyashiv cites the Mishnah in Zevachim which discusses 'Tit ha'Neirok' - soft mud that is not eligible to form a Mikvah ...

(b)... yet the Tana rules there - that combines to complement a Mikvah of forty Sa'ah ...

(c)... and by the same token - Pasul Sechach of less than three Tefachim will complement a Sukah to render it Kasher.

7)

(a)Rebbi Eliezer invalidates a Sukah that is shaped like a 'Tzerif' - (a hut in which bird-trappers await their catch which is shaped like a beehive) or one that is leaning against a wall at an angle ...

(b)... because the roof is not distinguishable from the wall, and a sloping Ohel is not considered an Ohel (i.e. it must be ninety degrees to the wall).

(c)The Rabanan rule - that they are Kasher, because they hold that a sloping Ohel is considered an Ohel.

8)

(a)Rebbi Eliezer in a Beraisa, concedes that if one raises the floor of the Sukah one Tefach, the Sukah is Kasher - since it now has an Ohel measuring a Tefach.

(b)This ruling pertains - to both of the two cases in our Mishnah.

(c)Alternatively, the Tana suggests that one renders Kasher the latter Sukah in the Mishnah - by moving it one Tefach away from the wall.

9)

(a)The Rabanan declare Kasher the two Sukos in our Mishnah - because they hold that a sloping Ohel is considered an Ohel.

(b)When Abaye found Rav Yosef sleeping under a Kilas Chasanim (a sort of two-poster bed) in a Sukah, he asked him - whether he held like Rebbi Eliezer.

(c)The latter justified ...

1. ... his actions - by referring to a Beraisa, where Rebbi Eliezer and the Rabanan switched their opinions, in which case, he was actually following the opinion of the Rabanan.

2. ... his giving precedence to a Beraisa over a Mishnah - inasmuch as he learned from another Beraisa that the author of our Mishnah is the minority opinion of Rebbi Nasan (quoting Rebbi Eliezer), and that the Rabanan actually invert the opinions.

10)

(a)The Tana Kama in our Mishnah rules that a large cane mat that is made ...

1. ... to lie on - is Pasul regarding Sechach, and is subject to Tum'ah.

2. ... specifically for Sechach - is Kasher for Sechach and not subject to Tum'ah.

(b)Rebbi Eliezer rules that both a small mat and a large one - is Pasul and subject to Tum'ah, if it is made to lie on, and Kasher and not subject to Tum'ah, if it is made for Sechach.

(c)The two statements of the Tana Kama appear to clash - since the first one implies that Stam is Kasher for Sechach and not subject to Tum'ah, whereas the second one implies just the opposite.

(d)To resolve the discrepancy, we establish the Tana Kama's ...

1. ... first statement - by a large mat, and his ...

2. ... second statement - by a small one.

11)

(a)when the Tana Kama says 'le'Sikuch, Mesachechin Bah ...', he now means - that if a small mat is made for Sechach, it is Kasher, but that Stam, it is meant for lying on, and is therefore Pasul.

(b)The problem that the above explanation creates regarding Rebbi Eliezer's two statements is - that we are presented with same discrepancy between them as we were faced with according to the Tana Kama. Only this time we cannot answer like we did the Tana Kama, since he specifically said 'Achas Ketanah v'Achas Gedolah'.

12)

(a)To put the Mishnah in its right perspective - Rava interprets 'le'Sikuch', both of the Tana Kama and of Rebbi Eliezer - to mean Stam.

(b)With that, he tries to answer that both Tana'im declare Kasher a Mechtzeles Gedolah Stam, and he interprets the statement 'le'Sikuch Mesach'chin Bah v'Einah Mekabeles Tum'ah' of ...

1. ... the Tana Kama to mean - that a Stam large mat is Kasher for Sechach (but not a small one), whereas ...

2. ... Rebbi Eliezer - declares Kasher both a Stam small mat and a large one.

(c)According to Rava then, they are arguing over whether a Stam small mat is Kasher for a Sukah and therefore not subject to Tum'ah (Rebbi Eliezer) or subject to Tum'ah and Pasul (the Tana Kama).