Shiur summary (draft from the recording)
Matching Rav's parameters to the three reasons
Sukkah 2b · Thursday, March 26, 2026
The sugya
The Gemara gave three reasons why a sukkah above 20 amos is pasul: the eye does not register it (Rabbah), no shade (R' Zeira), and dirah keva (Rava). Now it brings three statements in the name of Rav that limit the machlokes in the Mishnah with parameters rather than reasons, and asks whom each goes like. R' Yoshiyah fits Rabbah, Rav Huna fits R' Zeira, and Rav Chanan bar Rabbah fits no one. The Rebbi added a possible fourth reason (a narrow, tall sukkah looks like a chicken coop) and reviewed the matches.
Step by step (shakla v’tarya)
- ChazarahReview: three Amoraim gave reasons why the Chachamim pasul a sukkah above 20: you can't see the schach, you don't get shade, or it is keva.
- The next three Amoraim, all in the name of Rav, give parameters, not reasons. The Gemara matches each parameter to a reason.
- The RebbiThe Rebbi suggested that since all three are said in the name of Rav, perhaps Rav said one thing and they are unsure what he said. After discussion with the chabura he left it open ('I have to think about that').
- GemaraR' Yoshiyah amar Rav: the machlokes is only where the walls don't reach the schach. If the walls reach the schach, it is kosher even above 20 amos.
- TeirutzThis goes like Rabbah. His reason is that the eye won't register schach above 20, but if the walls reach the schach, the eye surely registers it.
- The RebbiIn their Mediterranean climate, open sukkahs were normal: low mechitzos and poles holding high schach. Walking in, you see only the low walls, not what is far above. If the walls go all the way up, it is like a house and you know there is schach on top.
- GemaraRav Huna amar Rav (line 12): the machlokes is only in a sukkah of exactly 4 amos by 4 amos (about 8 by 8 feet). If it is more than 4 by 4, it is kosher even above 20 amos.
- TeirutzThis goes like R' Zeira, who says the reason is shade. Since the sukkah is wider (rvicha), there is tzeil sukkah, which is basic geometry.
- The RebbiThis works as a ratio: the wider you go, the higher you can go, and it works both ways. R' Zeira's approach is mathematical (shade and spans). Rabbah's is human perception: a person perceives something very high as long as something takes the eye from the floor all the way up.
- GemaraRav Chanan bar Rabbah amar Rav (lines 17-18): the machlokes is only where the sukkah holds just rosho v'rubo v'shulchano. If it holds more, it is kosher even above 20 amos.
- 'Rubo' refers to the torso. They ate leaning on the left side, each person at his own small table.
- The RebbiThis is the famous 7 by 7 (zayin al zayin) minimum sukkah, which comes up a lot in the first perek. Hechsher sukkah means a place where at least one person could live.
- According to Rav Chanan bar Rabbah, the 20-amah limit applies only to a sukkah of exactly the minimum size. With even slightly more (for example 7.1 by 7.1), it is kosher above 20.
- MaskanaWhom does this go like? No one (d'lo k'chad). An extra bit of space makes the sukkah no shadier and no more or less keva; the Rebbi asked whether it is like a kind of kenas.
- ShitahA talmid asked about a fourth reason. The Rebbi cited a view (name unclear in recording): a very narrow sukkah that goes up very high looks like a chicken coop, which was kept narrow and tall, perhaps for ventilation. It is not called a sukkah; people would say he is raising chickens.
- A talmid recalled that chicken coops were put on rooftops. The Rebbi said 'very good', perhaps so.
- ChazarahReview: Rabbah (eyesight) fits walls reaching the top. R' Zeira (shade) fits a wider sukkah. No parameter fits Rava's keva reason.
- A talmid connected this to Rava standing alone earlier because of Abaye's kasha. The Rebbi: logically, Rava says up to 20 you build something that stands for seven days and comes down; above that, there is no parameter.
- ChazarahThe Gemara on line 18 was read inside again: Rav Chanan bar Rabbah's parameter is like no one.
Kashas
- Kemana azla: whom does R' Yoshiyah's parameter (walls reach the schach) go like?
- Kemana azla: whom does Rav Huna's parameter (more than 4 by 4 amos) go like?
- Kemana azla: whom does Rav Chanan bar Rabbah's parameter (more than rosho v'rubo v'shulchano) go like?
- Why does no parameter fit Rava's keva reason? A talmid asked whether this relates to Abaye's kasha on Rava.
Teirutzim
- R' Yoshiyah goes like Rabbah: when the walls reach the schach, the eye registers it.
- Rav Huna goes like R' Zeira: a wider sukkah gives tzeil sukkah.
- Rav Chanan bar Rabbah goes like no one.
- Up to 20 you can build something temporary for seven days; above that, there is no parameter.
Mareh mekomos
- The earlier Gemara (Rabbah, R' Zeira, Rava), whose reasons are matched to the new parameters.
- Abaye's kasha on Rava from the earlier Gemara, raised regarding why no parameter fits Rava.
- A view giving a fourth reason, the chicken coop (name unclear in recording).
The Rebbi’s chiddushim
- Since all three are in the name of Rav, perhaps Rav said only one thing and it was unclear what he said. Left open.
- Open Mediterranean sukkahs with low walls and high schach explain Rabbah: you see only the walls unless they reach the top.
- R' Zeira's shade reason works as a ratio of width to height. It is mathematical, while Rabbah's is about perception.
- Rav Chanan bar Rabbah's parameter gives no reason for allowing more height; it is perhaps like a kenas.
- A narrow, very tall sukkah looks like a chicken coop and is not called a sukkah.
Unclear in recording
- Part of the discussion with the chabura on whether the three statements in the name of Rav argue with each other.
- Parts of the exchange about Abaye's kasha and Rava.
- The Rebbi's remarks about a pottery lamp in connection with zayin al zayin.
- Name of the authority cited for the chicken-coop reason.
- A remark that sounded like 'Rashi doesn't say that'.
Drafted from the recording of the shiur, for chazarah. Torah terms follow the Rebbi’s own words; anything that could not be made out is marked “unclear in recording”. Tap a time to hear that point. Corrections welcome.