Shiur summary (draft from the recording)
Rabbi Yochanan's round sukkah of 24 people
סוכה העשויה ככבשן
Sukkah 8a · from line 6 · Thursday, July 2, 2026
The sugya
The shiur continues the calculation behind Rabbi Yochanan's statement that a round sukkah needs room around it to seat 24 people, which follows Rebbi's requirement of 4 by 4 amos. A 4 by 4 square has a diagonal of 5.6, so the circle around it needs a circumference of 16.8. The Gemara works through several approaches. 'Lo dak' fails when the gap is large. Mar Kashisha's 'three men in two amos' gives 16, which is too little, because lo dak applies only l'chumra. Rav Assi then explains that Rabbi Yochanan did not count the place of the men themselves: they sit around the outside of the circle. The inner circle is then 18, and that is lo dak l'chumra.
Step by step (shakla v’tarya)
- ChazarahReview: Rabbi Yochanan's round sukkah of 24 people must follow Rebbi's shita of 4 by 4 amos. 24 people give 16 amos, but the circle needs 16.8, so Rabbi Yochanan was not fully precise.
- GemaraLine 7: every amah of a square's side is an amah and two-fifths on the diagonal. A 4 by 4 square has a diagonal of 4 x 1.4 = 5.6, and 5.6 x 3 = 16.8, which is 'shiv'sar nachei chumsha' (17 less a fifth).
- KashaLine 9: if 16.8 is enough, why did Rabbi Yochanan say 24 people, taking each man as an amah?
- TeirutzRabbi Yochanan was not precise (lo dak).
- DechiyahWe say lo dak only when someone is off by a little. Here he is off by a lot, about 8 (16.8 against 24).
- TeirutzMar Kashisha to Rav Ashi: a man does not take a full amah; three men sit in two amos. 24 people therefore take 16 amos.
- KashaBut we need 17 less a fifth (16.8), not 16.
- TeirutzNow he is off by very little, so we can say lo dak.
- DechiyahLine 15: we say lo dak only l'chumra. Here 16 comes in under the required 16.8, which is l'kula, and we do not say lo dak l'kula.
- TeirutzSecond-to-last line: Rav Assi to Rav Ashi. A man really does sit in an amah, but Rabbi Yochanan did not count the place of the men ('makom gavri lo kachashiv'). The 24 men sit around the outside of the circle.
- MaskanaLine 17: the outer circle is 24 with a diameter of 8. Taking off an amah on each side leaves a diameter of 6, so the inner circle is 6 x 3 = 18. With 17 less a fifth it is enough, so this is the lo dak, and it is lo dak l'chumra.
- The sugya ends with one more statement, which the Rebbi called more bizarre rather than harder. It is to be learned next time.
Kashas
- If a circumference of 16.8 is enough, why did Rabbi Yochanan require room for 24 people?
- With three men in two amos, 24 people give only 16, but 16.8 is needed.
- Lo dak cannot explain being off by about 8 amos.
- Lo dak cannot be said l'kula, when the number falls below what the halacha requires.
Teirutzim
- Rabbi Yochanan was not precise (rejected, since the gap is too large).
- Mar Kashisha: three men take two amos, giving 16 (rejected, since that is lo dak l'kula).
- Rav Assi: each man takes an amah, but the men sit outside the circle, so their own place is not counted. The inner circle is 18, which is lo dak l'chumra.
Mareh mekomos
- Rebbi's shita that a sukkah needs 4 by 4 amos, as the basis for Rabbi Yochanan's measurement.
The Rebbi’s chiddushim
- Mashal for not saying lo dak l'kula: if I owe a friend $521, I cannot say I owe $520, but saying $525 is fine (the Rebbi joked about ribbis).
- The psak itself is exact and never changes: a round sukkah needs a circumference of 16.8 (4 by 4 square, diagonal 5.6, times 3). Only Rabbi Yochanan's use of people as a measuring tool is imprecise. With the three-men-in-two-amos calculation he would have had to say 25.
- Zmanim are the same: when giving a rounded time such as candle-lighting before shkiah, you must round to the safe side, at least 18 minutes before shkiah.
- The Rebbi suggested that Rav Ashi is mentioned throughout because he was apparently the one everyone consulted on these calculations (said tentatively).
- Rav Assi does not mean a halacha that people sit outside the sukkah. The 24 men are only a measuring tool, so the word 'bah' (k'dei leishev bah) is not meant literally.
- Picture the slices of a pizza: the outer edge (crust), where the men sit, is larger than the inner edge, which is the actual sukkah wall (a talmid's comparison, accepted).
- Lashon: 'tamanisre' is tamani (8) plus sre (10) = 18, though shiv'sar is said as one word. 'Sagya' is written without an aleph on line 3 and with an aleph here; the Rebbi said he does not know why.
Unclear in recording
- The exact shkiah times in the example (8:20 / 8:30) were unclear.
- A remark about the word 'bah' and the phrase that follows it was partly garbled.
- A side discussion about learning this type of material with someone else was unclear.
- 'A lot of the history we'll do next week' was unclear in the recording.
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.