Shiur summary (draft from the recording)
Round sukkah: Rebbi Yochanan's twenty-four people
סוכה העשויה ככבשן
Sukkah 7b · from line 18 · Thursday, June 25, 2026
The sugya
The shiur began by reviewing Abaye's list of Tannaim who all hold that a sukkah must be a dira keva. It then moved to Rebbi Yochanan: a round sukkah (like a kivshan) is kosher only if its circumference can seat 24 people. The Gemara attributes this to Rebbi, who requires 4 by 4 amos, and starts its first 'midi' calculation. A circle with a 4-amah diameter gives a circumference of 12, and the extra space of a square raises it to 16. Both still fall far short of 24, and the Rebbi said the rest of the math will be taken slowly in the next shiur.
Step by step (shakla v’tarya)
- ChazarahReview from the previous day: Abaye lists Rebbi, R' Yoshiya, R' Yehuda, R' Shimon, Rabban Gamliel, Beis Shammai, R' Eliezer and Acherim. All of them hold that a sukkah needs an aspect of permanence (dira keva).
- ChazarahRebbi: a sukkah must be at least 4 amos by 4 amos. That is fairly big, so it is more keva.
- ChazarahR' Yoshiya, as just learned: even the walls must have a certain integrity.
- ChazarahR' Yehuda, from our Mishnah: he is machshir a sukkah higher than 20 amos.
- ChazarahR' Shimon needs more walls than the Chachamim. The Chachamim require two kehilchasan and the third even a tefach. R' Shimon requires three kehilchasan and the fourth even a tefach.
- ChazarahRabban Gamliel is posel a sukkah on top of a wagon or a boat, and R' Akiva is machshir. The Rebbi explained that it is too wobbly and not set in one place, so it lacks permanence.
- ChazarahBeis Shammai are posel one whose head and most of his body are in the sukkah while his table is in the house. They too require an aspect of permanence.
- ChazarahA sukkah made like a tzrif is pasul (in the Gemara this is R' Eliezer's case; the name is unclear in recording). The Rebbi described it as like a tipi, made entirely of bamboo and coming to a point.
- The Rebbi mentioned hearing in another shiur that, of all these opinions, the only one we actually pasken like is Beis Shammai.
- GemaraRebbi Yochanan: a sukkah made like a kivshan, meaning round, has a rule. If its circumference can seat 24 people, it is kosher; if not, it is pasul.
- RashiRashi says right away that kivshan means round.
- The RebbiThe 24 people are counted sitting around the edge with their backs against the wall. This measures how wide the circle is.
- KashaTwenty-four is a lot of people. Why should a round sukkah need such a big circle?
- MaskanaKemaan? The Gemara answers: like Rebbi, who says any sukkah that does not have 4 amos on 4 amos is pasul. Somehow a sukkah of 4 amos will have to work out to 24 people.
- GemaraMidi (the first one in the masechta). First principle: gavra b'amsa yasiv, a seated man takes up an amah.
- GemaraSecond principle: anything with a circumference of 3 tefachim has a width (diameter) of 1 tefach. This is the Gemara's rounded version of pi, a ratio of three to one.
- KashaB'trisar sagi: twelve should be enough. Rebbi's 4-amah line, with a circle drawn around it, gives 4 times 3, which is 12 amos of circumference, so 12 people.
- TeirutzHanei mili b'igula, aval b'ribua ba'i tfei. The one-to-three ratio is for a circle, but Rebbi is speaking of a square, which needs more.
- The RebbiPicture a circle inside a square. All the corner areas outside the circle must also be included if you make a round sukkah, because Rebbi requires that amount of space.
- GemaraHow much more is a square than a circle? A quarter more.
- MaskanaB'shitsar sagi: sixteen should be enough. The perimeter of Rebbi's square is 4+4+4+4, which is 16. Make that perimeter into a circle and you have 16.
- RashiRashi gives an example: take a string and measure, or take the same four-by-four walls and form them into a circle.
- KashaEven sixteen is still far from 24. Twelve was a massive question, and sixteen is still a question.
- To be continued. The Rebbi urged going over the calculation many times.
Kashas
- Why should a round sukkah need room for as many as 24 people?
- According to Rebbi, a circle around a 4-amah diameter has a circumference of 12, so 12 people should suffice. Twenty-four is double Rebbi.
- Even after counting the square's extra space, 16 should suffice. That is still far from 24.
Teirutzim
- Rebbi Yochanan follows Rebbi, who requires 4 by 4 amos.
- The one-to-three ratio applies to a circle. Rebbi requires a full square, which is more, namely a quarter more, giving 16.
Rashi & Tosafos
- Rashi: Kivshan means round.
- Rashi: Example: measure with a string, or take the same four-by-four walls and shape them into a circle, to show that the square's perimeter becomes the circle's circumference.
Mareh mekomos
- Our Mishnah (sukkah above 20 amos), cited as the source of R' Yehuda's opinion.
- Another shiur the Rebbi heard: of all the opinions in Abaye's list, we pasken only like Beis Shammai.
The Rebbi’s chiddushim
- Rabban Gamliel's psul of a wagon or boat is because it is wobbly and not fixed in place, so it lacks permanence.
- The 24 people sit around the edge with their backs to the wall. This is how the circle's size is measured.
- An amah is roughly close to two feet; he gave a range of about 17-18 to 22 inches.
- Visualise the circle inscribed in a square. The corners are the extra space Rebbi's square includes, and a round sukkah must account for it.
Unclear in recording
- An exchange about Rebbi's three measurements of a sukkah, and which one Rebbi Yochanan must follow, is garbled.
- Remarks that the extra quarter is 'nearly nine' and gives 'three more seats' are unclear.
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.