(Mishnah - R. Eliezer): Lechayayim...

Question: Does R. Eliezer require a Korah in addition to Lechayayim?

Answer (Beraisa): A case occurred in which R. Eliezer visited his Talmid R. Yosi ben Freida. He found him in a Mavoy with only one Lechi, and told him to make another.

R. Yosi: Must I seal it?!

R. Eliezer: Seal it! This is no problem!

R. Shimon ben Gamliel says, Beis Shamai and Beis Hillel agree that nothing is needed to permit a Mavoy less than four Amos. They argue about a Mavoy between four and 10 Amos. Beis Shamai require a Lechi and Korah, Beis Hillel require a Lechi or Korah.

Summation of answer: R. Yosi called this sealing off the Mavoy. Granted, Lechayayim and a Korah is like sealing it, but Lechayayim alone is not!

Rejection: He meant 'must I seal it with Lechayayim?!' (See note 4 in Appendix.)

(Beraisa - R. Shimon ben Gamliel): Beis Shamai and Beis Hillel agree that nothing is needed to permit a Mavoy less than four Amos.

Question: In our Mishnah, R. Yishmael cited a Talmid to say that all agree that a Lechi or Korah permits a Mavoy less than four Amos [and R. Akiva agreed that something is needed to permit it]!

Answer (Rav Ashi): R. Shimon ben Gamliel means that a Mavoy less than four does not need a Lechi and Korah like Beis Shamai, nor Lechayayim like R. Eliezer. Rather, a Lechi or Korah suffices, like Beis Hillel.

Question: What is the minimum [width] that needs something to permit it?

Answer (Rav Achli): It is four Tefachim.

(Rav Sheshes): Chachamim agree with R. Eliezer about remnants of a [breached wall of a] Chatzer. (We require remnants on both sides);

(Rav Nachman): The Halachah follows R. Eliezer regarding remnants of a Chatzer.

(Rav Nachman bar Yitzchak): The Chachamim [whom Rav Sheshes says agree with R. Eliezer] are Rebbi. Rav Nachman says that the Halachah follows R. Eliezer. This implies that they argue [about a Chatzer]!

Question: Who is the Tana who argues with R. Eliezer?

Answer: It is Chachamim [who argue with Rebbi]:

(Beraisa): One remnant (Rashi - at one end of the breached wall; Rabbeinu Yehonason (on the Rif) - or in the middle) permits a Chatzer;

Rebbi says, two remnants [at the ends] permit.

(Rav Asi citing R. Yochanan): A Chatzer requires two remnants.

Question (R. Zeira): You yourself said in the name of R. Yochanan that remnants of a Chatzer must be four Tefachim!

Suggestion: He means that four Tefachim are required on each side.

Rejection: (A Mishnah teaches that if a small Chatzer was breached to a big Chatzer, the big Chatzer is permitted.) Rav Ada bar Avimi's Beraisa says that the small Chatzer is 10 [Amos wide], and the big Chatzer is 11. (It is only one Amah wider. There is no room for remnants of four Tefachim on each side!)

Answer (R. Zeira): If there is only one remnant, it must be four Tefachim. If there are remnants on both sides, they can be any size;

Rav Ada's Beraisa is like Rebbi [who requires two remnants]. He holds like R. Yosi [that each remnant must be three Tefachim. R. Yochanan holds like Chachamim, who require one remnant of four, or of any amount on both sides].

(Rav Yosef citing Rav Yehudah citing Shmuel): One remnant permits a Chatzer.

Question (Abaye): Shmuel told Rav Chananyah bar Shila not to permit unless the majority of the wall remains, or there are remnants on both sides!

Rav Yosef: I just know that a case occurred in a village of shepherds in which a strip from the sea entered a Chatzer (the wall was breached - see Perush Chai diagram, Perek 1 number 158, in the English Charts section), and Rav Yehudah required only one remnant.

Abaye: You cannot learn from there. Chachamim were lenient about [Mechitzos by] water!

Question (R. Tavla): Does a hanging Mechitzah permit carrying in a ruined house?

Answer (Rav): Chachamim gave this leniency only regarding water (86b; see Perush Chai diagram, Perek 1 number 160, in the English Charts section).

Abaye's question remains!

Answer (Rav Papa and Rav Huna brei d'Rav Yehoshua): Shmuel says that one remnant permits if it is four Tefachim. If there are remnants on both sides, they can be any size.

Question (Rav Papa): Still, this does not explain why Shmuel told Rav Chananyah to require the majority of the wall or remnants on both sides. Four Tefachim suffice!

Suggestion: He refers to the majority of a seven Tefachim wall. Four Tefachim is the majority!

Rejection: If so, it would suffice for anything more than three Tefachim to remain [for then the opening is less than four Tefachim]!

(Rav Achli): The minimum [width that needs something to permit it] is four Tefachim.

Answer #1: Rav Achli discussed a Mavoy, but a Chatzer needs something to permit it even if it (the opening) is less than four Tefachim;

Answer #2: Tana'im (13b) argue about Rav Achli's law.

(Beraisa): If a strip from the sea enters a Chatzer, one may not draw water from it on Shabbos unless there is a Mechitzah 10 Tefachim tall;

This is if the wall was breached more than 10 [Amos]. If the gap is at most 10, nothing is required.

Inference: The Beraisa forbids drawing water from it (Rashi; Tosfos - transferring between the Chatzer and the house). It does not forbid carrying in the Chatzer.

Question: The Chatzer is totally breached (i.e. more than 10) to an area to which one may not carry! (This should forbid the Chatzer itself.)

Answer: The case is, there are Gedudei (Rashi - remnants of the breached wall that are 10 Tefachim tall, just they are covered by water; R. Tam - banks 10 Tefachim tall on each side of where the water enters).

(Rav Yehudah): (One may not carry in a Mavoy unless there is Shituf, i.e. food jointly owned by members of the Chatzeros.) If Shituf was not made in a Mavoy:

If it was Huchshar through a Lechi, one who throws to it [from Reshus ha'Rabim] is liable;

If it was Huchshar through a Korah, one who throws to it is exempt.

Inference (Rav Sheshes): The exemption in the latter case is because Shituf was not made. However, if Shituf was made, in both cases one who throws to it is liable.

Objection (Rav Sheshes): Surely, a loaf [for Shituf] cannot make it Reshus ha'Yachid or Reshus ha'Rabim!

(Beraisa): If one threw [from Reshus ha'Rabim] to a Chatzer of Rabim (many houses open to it) or to a Mavoy that is not Mefulash, he is liable, whether or not an Eruv was placed.

Correction (Rav Yehudah): If Shituf cannot be made in a Mavoy (Rashi - because it is Mefulash; Rashash - if so, it would need Tzuras ha'Pesach! R. Chananel - if a Mavoy Mefulash was Huchshar for Shituf through Tzuras ha'Pesach on the third side):

If it was Huchshar through a Lechi, one who throws to it is liable;

If it was Huchshar through a Korah, one who throws to it is exempt.

Inference: He holds that a Lechi is considered a Mechitzah, but a Korah is only a Heker. This is like Rabah;

(Rabah): A Lechi is a Mechitzah. A Korah is only a Heker.

(Rava): Both of these are only Hekerim.

Question (R. Yakov bar Aba - Beraisa): If one throws to a Mavoy:

If it has a Lechi, he is liable. If not, he is exempt.

Answer (Rava): It means that if it needs only a Lechi (it already has three walls, which makes Reshus ha'Yachid mid'Oraisa), he is liable. If it needs more than a Lechi (it is Mefulash), he is exempt.

Question (Beraisa): R. Yehudah said an even bigger Chidush. If one owns two houses on opposite sides of Reshus ha'Rabim, he puts a Lechi on each side [of one house], or a Korah on each side, and he may carry in the middle. (This shows that Lechayayim and Koros are Mechitzos. Seemingly, it refutes not only Rava, rather, even Rav Yehudah and Rabah! R. Akiva Eiger - they can say that they hold like R. Yakov's Beraisa, which holds that a Lechi is a Mechitzah, but a Korah is not.)

Chachamim: We cannot be Me'arev Reshus ha'Rabim like this!

Answer: R. Yehudah holds that two walls make a Reshus ha'Yachid mid'Oraisa. (The Lechayayim are needed only mid'Rabanan.)

(Rav Yehudah): If the length of a Mavoy equals its width, a Lechi Mashehu (arbitrarily thin) does not permit it.

(Rav Chiya bar Ashi): If the length of a Mavoy equals its width, a one-Tefach thick Korah does not permit it.

Support (for both of them - R. Zeira): Since its length equals its width, it is like a Chatzer [in which one of the walls was breached]. A Lechi or Korah does not permit it. It requires a remnant [on one side that is four Tefachim wide. Some delete this from the text, for R. Zeira himself suggests that less should suffice.]

Question (R. Zeira): A Lechi should be considered a remnant Mashehu, and permit!

Answer: He forgot Rav Asi's teaching:

(Rav Asi citing R. Yochanan): Remnants of a Chatzer must be four Tefachim.

(Rav Chiya bar Ashi): If the length of a Mavoy equals its width, a Korah a Tefach thick does not permit it.

(Rav Nachman): We have a tradition that a Lechi or Korah permits a Mavoy only if its length exceeds its width, and houses and Chatzeros are open to the Mavoy. (Rashi - one house opens to each Chatzer. Rashi (74a) - two open to each Chatzer);

A Lechi or Korah does not permit a Chatzer. Rather it requires a remnant four Tefachim wide, if it is square.

Question: This implies that a round Chatzer is permitted through a Lechi or Korah!

Answer: No. It means that if the length exceeds the width, it is a Mavoy, and a Lechi or Korah permits it. If not, it is a Chatzer.

Question: How much [must the length exceed the width to be considered a Mavoy]?

Answer #1 (Shmuel): It must be twice as long as its width.

Answer #2 (Rav, citing R. Chiya): The length can be Mashehu more than the width.