Today’s daf begins by discussing ways in which one could or could not reduce the height a sukkah that is already more than 20 cubits high by adding material to the base of the sukkah. The general principle here is that such a reduction in height is effective if we are sure that he has abandoned the material he used to reduce the height, and he won’t remove the material to use it during the week. If he has not abandoned it, the sukkah remains invalid lest he remove the substance he used to reduce the height and the sukkah would again be over 20 cubits high
He puts pillows and cushions on the ground so that the sukkah (the skhakh) is now no longer 20 cubits high. Such a reduction is not valid because we assume that when he sees people walking on the pillows or cushions, he will want to remove them. If he does so, the sukkah will again be more than 20 cubits high. Even if he specifically declares that he is going to “abandon” the pillows and cushions there, since most people wouldn’t do so, his intention is irrelevant.
Straw and earth can be used to reduce the height of the sukkah, as long as he declares that he has no intention to come back later during the week and use them for some other purpose.
Now the Talmud deals with two categories of situations in which earth or straw were used to reduce the height of the sukkah. 1) Straw which he did not intend to remove, but neither did he explicitly declare that he intended to leave it there; 2) Earth which he put there but we don’t know if he intended to leave it there or not. This is related, according to the Talmud, to a dispute between R. Yose and the other rabbis.
The mishnah they is from Ohalot 15:7. The mishnah teaches that if he filled the house with straw or gravel and then abandoned it there, the empty space of the house has been reduced. The issue in Ohalot is whether the impurity of a dead body in the house is trapped in the house or whether it goes up and down beyond the house. However, this is not relevant to us. What is relevant is that according to this opinion, he must expressly abandon the straw there. If not, it is not deemed to be part of the house.
However, R. Yose holds that he does not need to expressly abandon the straw there. As long as he has no express intention of removing it, it is considered to be part of the house.
This same debate would hold true with regard to the sukkah: according to the sages he would have to expressly abandon the straw or earth, whereas R. Yose would hold that it is sufficient to simply not intend to remove it.
But if he intends to remove the earth from the sukkah, it is like regular straw which he did not specifically intend to remove. Such straw or such the earth cannot be used to reduce the height of the sukkah because he may remove it later.
Today’s section continues to deal with reducing the height of a 20 cubit high sukkah.
If palm leaves were coming down from the roof of the sukkah, and they reduced its height to less than 20 cubits, the sukkah is valid as long those palm leaves provide more shade than the sun they let in. In other words, we’d have to estimate what would occur if we removed the upper skhakh. If the palm-leaves that are within 20 cubits would themselves constitute valid skhakh by providing more shade than sun, the sukkah is kosher.
The Talmud now examines whether these palm-branches coming down off the roof would serve to invalidate a sukkah that was 10 handbreadths high by making it too small.
Abbaye tried to apply the same principle from above. If the lowered-down palm branches don’t provide shade, meaning they let in more sun than shade, then they don’t count and the sukkah is valid.
Rava counters that such a sukkah is a “lousy dwelling place.” One couldn’t even sit in such a sukkah because the branches would bother him. Therefore it is invalid.
In this case he builds a ledge in the middle of the 20 cubit high sukkah. If he builds it out from the middle wall of three walls and the ledge goes out at least for the minimum breadth of a sukkah, then the sukkah is valid. Note that the entire sukkah is valid, not just the part over the ledge. Since the ledge comes out of the middle wall, it joins all three walls.
If he built the ledge from a side wall, the sukkah is kosher only if it’s within four cubits of the opposite wall. If it is further than that, the entire sukkah is invalid.
The Talmud now asks a typical question—couldn’t we have known that which we just taught from elsewhere. We just learned that if there are less than four cubits from the valid part of the sukkah, where the ledge is, to the invalid part (higher than 20 cubits), then the sukkah is valid. This principle is called a “curved wall.” What it means is that one can fictitiously imagine a wall that is not directly adjacent to the skhakh as if it was curved in to meet the skhakh.
The same is taught in Mishnah Sukkah 1:10—if one opens a hole in the ceiling of his house and puts skhakh on the hole, under the skhakh is a valid sukkah as long as there are less than four cubits between the valid skhakh and the walls of the house.
The Talmud now explains why we needed this baraita about the ledge. In the case of the house, all of the walls were proper walls. But here with the 20 cubit high sukkah, one wall is 20 cubits high because it has not been reduced by the ledge. We might have thought that such a wall could not be used. Therefore, we needed this baraita to teach us that even if the wall itself is invalid because it is too high, we can invoke the principle of the “curved wall.”
Today’s section continues with the case of a person building a platform inside a sukkah to reduce the size of the sukkah that is over 20 cubits high.
This is very similar to the previous case, but here he builds the platform right smack in the middle of the sukkah, not attached to any wall. Again, as we learned yesterday, if the platform/ledge is less than four cubits from the walls, the walls are considered its walls and we now have a sukkah that is less than 20 cubits high.
The Talmud now asks a logical difficulty. If the principle we learn here is again “the curved wall”—one can treat a wall removed by up to 4 cubits as if it were part of the sukkah—then we learned that in the previous section. Why do we need to learn it again.
The answer is that this section teaches us that the principle of the “curved wall” can be applied even if you have to “curve” all of the walls. In the previous case the platform or ledge was adjacent to one of the walls. In this case it is not adjacent to any wall. Therefore, this source had to teach that we can pretend that all of the walls go with this platform and the reduced height of the sukkah is valid.