Siman - Succah Daf 17
- אויר פוסל בשלשה סכך פסול פוסל בארבעה
The next Mishnah states, הרחיק את הסיכוך מן הדפנות שלשה טפחים פסולה – If one distanced the s’chach three tefachim from one of the walls, leaving three tefachim of open space between it and the wall, the succah is passul. Rashi explains that the entire succah is passul because it is viewed as lacking a wall, on account of the gap. Rabbah said he once found the talmidim of Rav saying in the name of Rav אויר פוסל בשלשה סכך פסול פוסל בארבעה – A strip of open airspace is posel a succah when it is three tefachim wide, and a strip of invalid s’chach posels a succah when it is four tefachim wide. Rabbah challenged their ruling that passul s’chach invalidates if it is four tefachim wide, citing the same Mishnah, which also teaches בית שנפחת וסיכך על גביו – If the roof of a house was breached in the center and one placed s’chach on top of it, if there is a distance of four amos between the wall of the house and the s’chach, the succah is passul. This implies that if a gap narrower than four amos does not disqualify? The talmidim answered Rabbah, that this case is not relevant, as both Rav and Shmuel said that this ruling was based on the halachah of דופן עקומה, in which less than four amos of invalid s’chach can be viewed as part of a bent wall. Their ruling of four tefachim concerns passul s’chach in the middle of the succah.
- Rabbah’s challenge to the talmidim and their response
Rabbah posed another challenge to the talmidim. The halachah is that if there is a strip of passul s’chach less than four tefachim wide, in the middle of the succah, and next to it there is a strip of open space less than three tefachim wide, the succah is kosher because there is not enough passul s’chach to invalidate it. Yet if one filled the open space with spits or other passul s’chach, the succah is passul because the width of the invalid material is not at least four tefachim . ולא יהא אויר הפוסל בשלשה כסכך פסול הפוסל בארבעה – But should not open space, which disqualifies a succah when just three tefachim wide, be as potent as passul s’chach, which disqualifies a succah when four tefachim wide? Since filling the gap with spits invalidates the succah, then leaving it empty should certainly invalidate it, for empty space is a more potent disqualifier than solid material. How, then, can they rule that when the gap is empty, it does not combine with the solid material to invalidate the succah? The talmidim responded that if the question is valid, then Rabbah would have the same challenge in a case of a strip of invalid s’chach less than four amos wide in the middle of a succah, next to an open space of less than three amos wide .
- Rabbah’s response that the cases cannot be compared
Rabbah responded to the challenge, by saying that there is no comparison. According to him, the Mishnah’s rule that four amos of passul s’chach invalidates the succah, is not based on דופן עקומה but is a Halachah LeMoshe MiSinai shiur that disqualifies a succah, whether the material is at the side of the succah or in the middle. And this strip of invalid material, which measures four amos wide only when it combines with open space, does not have the shiur to disqualify a succah, for since the shiurim for the invalid s’chach and open space are not equal, לא מצטרפי – they do not combine to make up the requisite minimum. But according to the talmidim, who state a shiur of four tefachim based on original reasoning that measurement is only significant משום הפלגה – because of a gap, they must therefore explain what difference it makes whether the separation is made through invalid s’chach alone or through a combination of invalid s’chach and open space.
