1)

(a)Abaye rules that if there is a space of three Tefachim in the Sechach of a large Sukah, part of which one filled in with canes or with metal spit-rods - the Sukah is Kasher ...

(b)... seeing as there is neither the Shi'ur of space nor that of Pasul Sechach to invalidate it.

(c)If one filled in the same gap, but in a small Sukah ...

1. ... with canes - the Sukah is Kasher, because of the principle of 'Lavud'.

2. ... with metal spit-rods - it will be Pasul ...

(d)... because (even though it does not have a Shi'ur either of space or of Pasul Sechach, to invalidate the Sukah) it is three Tefachim short of the Shi'ur Sechach of a Kasher Sukah.

2)

(a)The above ruling is said with regard to a gap running along the side of the Sukah. Rav Acha and Ravina argue over whether the same Din applies to a gap running across the middle of the Sukah. One of them invalidate the Sukah, even if one filled in part of the gap with canes - because in his opinion, the principle of 'Lavud' is confined to the side. It does not extend to the middle.

(b)Ravina (who is traditionally the lenient one whenever he and Rav Acha argue) bases his opinion on a Beraisa which discusses a beam that comes out of one wall but that does not reach the opposite one. This Halachah is learned in connection with - permitting carrying in a Mavoy.

(c)The Mishnah adds a case where two beams come out of two opposite walls but do not meet in the middle. The Tana rules in both cases - that the Eruv is valid.

(d)Rav Acha refutes Ravina's proof from there that Lavud applies in the middle just as it does by the side - by confining it to Hilchos Eruv, which are purely d'Rabanan.

3)

(a)The Mishnah in Ohalos discusses the status of Kelim that are in a room containing a skylight if there is a Mes in the room. If a room has a Tefach by Tefach skylight - objects that are ...

1. ... in the room are Tamei.

2. ... directly underneath the skylight remain Tahor.

3. ...in the room remain Tahor, if the piece of corpse is directly underneath the skylight.

(b)Rav Acha is trying to prove - that Lavud does not apply in the middle of a wall or the ceiling.

(c)Ravina refutes the proof however - by confining Hilchos Tum'ah to their own Halachos (which do not apply elsewhere).

(d)We cannot extend it to other areas of Halachah with a 'Binyan Av'- because its source is Halachah l'Moshe mi'Sinai (and we do not learn any other area of Halachah from a 'Halachah ... ').

4)

(a)Rebbi Yehudah b'Rebbi Ila'i declared Kasher ...

1. ... a room part of whose ceiling caved in, and on which one placed Sechach and ...

2. ... a type of small fish called Abruma.

(b)Rebbi Yishmael b'Rebbi Yosi instructed Rebbi Yehudah, in both cases - to explain himself ...

(c)... because according to his father ...

1. ... the Sukah is only Kasher if the breach is less than four Amos (due to 'Dofren Akumah', but no more).

2. ...it depended on the river: the Abruma of certain rivers was permitted, but of other rivers, it was forbidden - because the Sheratzim that are to be found in it are not discernable.

(d)Rebbi Yosi nevertheless permitted those that were caught in certain rivers - for the reason that Abaye will now disclose.

5)

(a)Similarly, Abaye permitted a type of small fish called Tzachnasa from the River Bav. We initially thought that this permitted due to the fact ...

1. ... it is a swift-flowing river - and non-Kasher fish, which have no spinal cord, could not survive in it.

2. ... its water is salty - and non-Kasher fish are unable to survive there because they do not possess scales.

(b)We refute these suggestions however - because non-Kasher fish are known to survive in similar salty, swift-flowing rivers.

(c)Abaye in fact permitted Tzachnasa - because the mud on the river bed of the River Bav does not breed insects.

(d)The significance of Ravina's statement that the rivers Eisan and Gamda were subsequently diverted into the Bav River is - that nowadays, even Abruma and Tzachnasa that one catches in the River Bav are forbidden too, since these other rivers carry the insects that they do breed into it.

6)

(a)We learned that placing Sechach on top of an Achsadra (a sun-porch) -that has posts that are placed at intervals of less than three Tefachim apart, constitutes a Kasher Sukah. The case is - that of a courtyard that is surrounded by a stoep (that is in turn surrounded by the walls of houses,), and the Sechach actually covers the courtyard (like the last case in our Mishnah).

(b)The posts render the Sukah Kasher - provided they are less than three Tefachim apart (due to the principle of 'Lavud).

(c)The posts are necessary - because the walls that surround the sun-porch are more than four Amos away from the Sechach.

7)

(a)Abaye validates it even if there are no posts. Rava declares it Pasul.

(b)The basis of their Machlokes is - whether the principle of 'Pi Tikrah Yored v'Sosem' applies to the vertical section of the roof surrounding the Sechach (Abaye) or not (Rava).

(c)Rava asked Abaye why, in that case, he does not also validate a three-walled Sukah whose middle wall has collapsed, and which has Sechach consisting of thick planks that are less than four Tefachim wide. He replied - that 'Pi Tikrah Yored v'Sosem' does not apply there, since, due to the fact that it is open at both ends, the Rabanan forbade it because it resembles an open Mavoy.

8)

(a)We try to connect the Machlokes between Abaye and Rava with that of Rav and Shmuel, who argue by Achsadra b'Bik'ah - a sun-porch in a field that is not attached to a house.

(b)A Bik'ah - has the status of a Karmelis regarding Shabbos.

(c)

1. Rav permits carrying on Shabbos even more than four Amos inside the Achsadra - because he holds 'Pi Tikrah Yored v'Sosem' (even by all four walls).

2. Shmuel disagrees - because (although he concedes that the principle of 'Pi Tikrah Yored v'Sosem' applies by three walls) he maintains that it does not apply to four walls.

(d)We now suggest - that Abaye holds like Rav (even where there are no walls! - See Tosfos), and Rava, like Shmuel.

9)

(a)We conclude that Abaye and Rava do not argue over Shmuel's ruling - by which we mean that Rav certainly holds like Shmuel, whereas Abaye does not.

(b)And they are arguing about - whether Rav will agree with their respective opinions or not. Abaye holds that Rav will certainly hold 'Pi Tikra Yored v'Sosem in the case of Achsadra by Sukah.

(c)Whereas Rava maintains that only says 'Pi Tikrah Yored v'Sosem' by Achsadra b'Bik'ah - because the walls are specifically made for the Achsadra. In the case of Achsadra by Sukah on the other hand - where the walls are made for the house, he will agree with him (Rava) that 'Pi Tikrah Yored v'Sosem' does not apply.

(d)'Pi Tikra Yored v'Sosem is a branch of - 'Gud Achis Mechitzasah'.