1)

(a)Rebbi Chananya ben Akavya says 'Gezuztera she'Yesh Bah Arba Amos al Arba Amos, Chokek Bah Arba'ah Tefachim al Arba'ah Tefachim u'Memale'. This Shi'ur (of twenty-four Tefachim square) leaves us the possibility of (theoretically) cutting the ten Tefachim of wood that remain on each side of the hole, from the hole to the end of the board and bending the wood downwards to form four Mechitzos surrounding a hole of four Tefachim square. These four Mechitzos Teluyos permit one to draw water via the hole - even though the walls do not reach the level of the water (just like the opinion of Rebbi Yehudah in our Mishnah).

(b)

1. Rebbi Yehudah does not necessarily agree with Rebbi Chananya ben Akavya: it is not because he holds of 'Gud Achis Mechitzasah' that he also holds of both 'Kof' (bend the wall) and 'Gud Achis' ... together.

2. Nor does Chananya ben Akavya necessarily agree with Rebbi Yehudah - because he only said 'Gud v'Kof' etc., by the Sea of Teverya, due to the fact that there are already other leniencies there (i.e. the fact that it is surrounded by a steep slope [which already acts as a Heker], and it is surrounded by towns and enclosures); otherwise, he may well not rely on Mechitzah Teluyah at all.

2)

(a)If the same plank (of which Rebbi Chananya ben Akavya speaks) would be lying on two brackets that were fixed to a wall, with the edge of the plank within three Tefachim of the wall, it would only need to be eleven Tefachim and a fraction of a Tefach wide by Ten Amos - because the wall will already count as one of the Mechitzos Teluyos. Consequently, we would only need ten Tefachim for the opposite wall, plus the Tefach and a bit that would be needed to add to the less than three Tefachim between the board the wall - to make up the four Tefachim of hold through which the water will be drawn.

(b)If the board was placed ...

1. ... near the wall but vertically - it would need to be ten Tefachim tall by six Tefachim plus two Mashehuyin, and would have to be placed four Tefachim from the wall. Consequently, the six Tefachim and two Mashehuyin would allow us to bend one a bit Tefachim at each end, to form a four Tefach hole and to bring the bent ends to within three Tefachim of the existing wall which will render them joined, due to 'Levud'.

2. ... within three Tefachim of a corner, rather than a wall - it would need to be ten Tefachim tall, and two Tefachim and two Mashehuyin wide (to bend it in the middle, one Tefach and a Mashehu towards one side of the corner, and one Tefach and a Mashehu towards the other, leaving a four Tefachim hole in the middle.

(c)The plank in the original case of Rebbi Chananya ben Akavya must have been placed on four poles stuck in the ground in the water. Note: As to why we do permit drawing water, even when the board is less than four Amos square, because of 'Pi Tikrah Yored v'Sosem' - see Tosfos 86b, DH 'Gezuztera'.

3)

(a)A stream of water that passes through a Chatzer has the Din of a Karmelis. In order to draw water from it one requires a Mechitzah that reaches within its banks, stretching from one bank to the other, both where it enters the courtyard and where it leaves it.

(b)A Mechitzah Teluyah only helps when it is clear that the Mechitzah was made especially for that purpose (such as the case of the pit in our Mishnah), but not here, where it would not.

(c)Rebbi Yehudah holds that a Mechitzah Teluyah does not need to be made specially for that purpose. Consequently, even the wall of the Chatzer will be effective, too.

(d)The Rabbanan counter that the Mechitzah Teluyah that was erected over the stream of Avel was effective only because it was not ten Tefachim deep and four Tefachim wide, so that it was not a Karmelis.

4)

(a)A stream of water that is less than ten Tefachim deep and four Tefachim wide - is not a Reshus on its own. Consequently, it adopts the status of the Reshus through which it passes. If it passes through ...

1. ... a Reshus ha'Rabim - it is considered a Reshus ha'Rabim.

2. ... a Reshus ha'Yachid - it is considered a Reshus ha'Yachid.

5)

(a)If a stream passes by the windows of a series of houses in a Mavoy or a Chatzer - the Tana Kama permits drawing water from the stream and placing the bucket on the bank outside his window, provided it is less than three Tefachim wide; Raban Shimon ben Gamliel permits it as long as it is not than four. The basis of their argument is what measurement constitutes a Makom Petur.

(b)The Gemara rejects the suggestion that they are arguing about the width of the stream - because then they would be arguing over the dimensions of a Karmelis, whereas we presume Rebbi Yochanan's description of a Karmelis as four by four Tefachim to be unanimous.

(c)Rav Dimi Amar Rebbi Yochanan forbids using a Makom Petur to switch from one Reshus to another - by Reshuyos d'Oraysa, whereas we are now permitting it by Reshuyos de'Rabbanan (i.e. where even if he were to carry directly, there would be no Isur d'Oraysa involved.

6)

(a)When the Gemara quotes Rebbi Yochanan (above [77a], who permits the residents of both courtyards to use a wall that is not four Tefachim wide, provided they do not switch from one Chatzer to the other -even when they are not Reshuyos d'Oraysa) - it is quoting the opinion of Ze'iri in Rebbi Yochanan; whereas Rebbi Yochanan in our Sugya, which permits switching by Reshuyos de'Rabbanan, is quoted by Rav Dimi.

(b)Ze'iri establishes the Machlokes between the Tana Kama and Raban Shimon ben Gamliel in the Beraisa by the width of the stream. The basis of their dispute is what are the dimensions of a Karmelis (the very explanation that we rejected, in 5b).

(c)When the Gemara asks 'v'Tehavi Ki Chorei Karmelis'? - it means to ask that, even if the stream does not have the dimensions of a Karmelis, it should still have the Din of a Karmelis, due to the fact that before it reaches the town, the stream is presumed to have been ten Tefachim deep and four Tefachim wide, in which case its continuation should be termed 'Chorei Karmelis' which (like the Din of Chorei Reshus ha'Rabim, which have the Din of a Reshus ha'Rabim), should have the Din of a Karmelis!?

(d)Rav Ashi says that even if there is a Din of Chorin by a Karmelis on principle, that is only if they are close to the actual Karmelis (such as the holes in a wall which adjoins a Karpaf of more than a Beis Sasayim), but not here, where the part of the stream in question is so far away from the part which is a Karmelis.

7)

(a)According to Ravina, the three and four Tefachim of the Tana Kama and Raban Shimon ben Gamliel respectively, do not concern the width of the stream, or even the width of the banks; they are arguing about the Mechitzos that were put up at both the entrance and at the exit of the stream, which were made of two sections with a gap in between: According to the Tana Kama, a gap of three Tefachim is no longer considered joined (because we only say 'Levud' until three Tefachim); whereas according to Raban Shimon ben Gamliel, we say Levud up to four Tefachim. (as we learnt above on Daf 9a).

8)

(a)A horizontal ledge suspended above the water will not permit one to draw water on Shabbos, according to the Tana of our Mishnah - because although he holds of 'Gud Achis Mechitzasah' even by a Mechitzah Teluyah), he does not hold of 'Kof v'Gud' (like Chananya ben Akavya does).

(b)A Mechitzah of ten Tefachim must therefore be attached to the ledge, either above it or below it.

(c)Rebbi Chananya ben Akavya permitted the men of Teverya to wrap with Atza (the waste of legumes) - even though they collected it from the fields early in the morning when it was covered with dew, and dew is one of the seven liquids which is Machshir Lekabel Tum'ah. The reason for this is because dew is only Machshir Lekabel Tum'ah when one is initially pleased with it and wants it; Whereas the men of Teverya did not go out early because they wanted the dew, but because by collecting the Atza early in the morning, they would save themselves the need to interrupt their work later in the day. In fact, they were indifferent towards the dew.

9)

(a)The third concession of Rebbi Chananya ben Akavya to the men of Teverya - was to permit them to dry themselves with a towel (though it is not clear in which way this is a special concession, considering that it appears to be unanimously accepted).

(b)Rebbi Shimon even permits one to carry the towel home after the bath (assuming that an Eruv exists in the town), and not to be obligated to place it on the window-sill like the Tana Kama.

(c)The Tana Kama forbids carrying the towel home on the grounds that one may come to wring out the towel.

(d)Chazal forbade giving the towel to the bath-attendants - because the bath-attendants were suspected of wringing them out.