Shiur summary (draft from the recording)
Trees as Sukkah Walls and Swaying Mechitzos
העושה סוכתו בין האילנות
Sukkah 24b · Friday, December 12, 2025
The sugya
The Mishnah says a sukkah built between trees, with the trees serving as its walls, is kosher. Rav Acha bar Yaakov says a mechitza that cannot stand in a normal wind (ruach metzuyah) is not a mechitza. The Gemara asks on him from our Mishnah and from several braisos, mostly from Eruvin. Each time it answers that the swaying parts were woven together (hutsa v'dafna). The shiur reviewed yesterday's two attempted proofs and then learned the braisa of the hill, the pit and the harvested patch in a field of standing grain.
Step by step (shakla v’tarya)
- MishnahOne who makes his sukkah between trees, and the trees are its walls, the sukkah is kosher.
- ShitahRav Acha bar Yaakov: any mechitza that cannot hold itself steady and not sway in a ruach metzuyah is not a good mechitza.
- KashaOur Mishnah says trees can be the walls of a sukkah, yet trees sway.
- TeirutzThe Mishnah is dealing with the hard part of the trees, the trunks.
- KashaBut there are also the leaves and branches of the trees, which do sway.
- TeirutzHe wove them together with hutsa v'dafna so that the wall does not sway in the wind.
- KashaIf so, what is the Mishnah coming to teach us?
- TeirutzOne might have thought there should be a gezeirah that he will come to make use of the tree, for example by hanging things on his walls, which are really a tree. The Mishnah teaches that this is not a concern and it is allowed.
- ChazarahReview of yesterday's first attempted proof, from Eruvin: if a pas had a tree, a fence or a mechitza of reeds, it is judged as a dyomad. The Rebbi holds the kasha there comes from the reeds, which sway. The answer is that he made it with hutsa v'dafna.
- ChazarahReview of the second attempted proof: a tree spreading over the ground whose branches are not raised from the ground. One may carry under it, though the branches should sway. Answer: he wove the branches together with hutsa v'dafna.
- KashaFollow-up kasha: if so, one should be able to carry under such a tree of any size. Why does Rav Huna brei d'Rav Yehoshua say one may carry only in a beis sa'tayim?
- TeirutzThat is a different reason. It is a dwelling whose use is for the air outside it, and any such dwelling allows carrying only in a beis sa'tayim. It has nothing to do with the soundness of the drooping branches.
- GemaraAnother braisa, from Eruvin. If someone made his place for Shabbos on a tel ten tefachim high, whose area is from four amos to a beis sa'tayim, he may carry there. The sides of the hill are viewed as mechitzos.
- GemaraThe same applies to a nekka, a pit ten tefachim deep with an area from four amos to a beis sa'tayim.
- GemaraThe same applies to a harvested patch (kamah ketzurah) surrounded by standing stalks.
- GemaraIn all three cases he may walk the whole area, and outside it 2,000 amos, the regular techum Shabbos.
- KashaIn the harvested patch the surrounding stalks sway back and forth. This is a mechitza that does not stand in the wind, a kasha on Rav Acha bar Yaakov. The hill and the pit are earth and do not move.
- TeirutzThere too he made it with hutsa v'dafna. Before Shabbos he wove the standing stalks together and strengthened them.
Kashas
- From our Mishnah, which allows trees as sukkah walls even though trees sway, on Rav Acha bar Yaakov.
- Even if the Mishnah means the trunks, the leaves and branches still sway.
- If the branches are woven together, what chiddush does the Mishnah teach?
- From the Eruvin braisa about a pas made of a tree, a fence or a mechitza of reeds. The Rebbi holds the kasha is from the reeds, which sway.
- From the tree spreading over the ground: one may carry under it, though the branches sway.
- If the woven branches are a proper mechitza, why may one carry only in a beis sa'tayim, as Rav Huna brei d'Rav Yehoshua says?
- From the harvested patch surrounded by standing stalks: one may walk there even though the stalks sway.
Teirutzim
- The Mishnah refers to the hard trunks.
- He wove the branches together with hutsa v'dafna so that they do not sway.
- The chiddush is that we do not make a gezeirah that he will come to use the tree.
- In the pas case too, he made it with hutsa v'dafna.
- In the tree case, the drooping branches were woven together and will not move.
- The beis sa'tayim limit is because it is a dwelling whose use is for the outside air, not because of any weakness in the mechitza.
- In the harvested patch, he wove the stalks together before Shabbos.
Mareh mekomos
- Braisa in Eruvin: a pas with a tree, fence or mechitza of reeds is judged as a dyomad. Brought as an attempted proof against Rav Acha bar Yaakov.
- Braisa in Eruvin: a tree spreading over the ground, under which one may carry. Brought as an attempted proof against Rav Acha bar Yaakov.
- Rav Huna brei d'Rav Yehoshua: under such a tree one may carry only in a beis sa'tayim.
- Braisa, which the Rebbi thinks is from Eruvin: the tel, the nekka and the harvested patch. Brought as another kasha on Rav Acha bar Yaakov.
The Rebbi’s chiddushim
- With hutsa v'dafna, wind may pass through the woven wall. The Rebbi does not think that is a problem, since the mechitza itself holds steady.
- With a dyomad, one need not actually see the two sides of the corner. One may envision the corner as carved out.
- In the pas braisa, the kasha is from the reeds, not from the tree.
- Example of a dwelling used for the outside air: a hut for watching the crops.
- The tel is pictured as a flat raised area. Its sloping sides are viewed as mechitzos, so a person stuck somewhere for Shabbos can use it without putting up walls.
- Nekka literally means a crack. Here it is a pit, the opposite of the hill: there it is 'high', here it is 'deep'.
- Kamah, standing grain, comes from the word kum. The case is a bald, harvested patch in a field with standing stalks all around it, like a corn maze.
- The 2,000 amos is the regular techum Shabbos. The limit applies wherever a person stays, unless the town continues on into the next village.
- On the harvested patch: he had enough time before Shabbos to weave the stalks together and prepared himself well.
Unclear in recording
- A talmid asked a kasha about the reeds in the pas braisa. His name and the exact exchange are unclear in recording.
- The size of a beis sa'tayim is garbled here (5,000 'square miles'). Later he gives it as up to five thousand square amos.
- The exact wording of the tree case regarding the height of the branches above the ground is unclear in recording.
- One phrase just before the teirutz on the harvested patch is garbled.
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.