Sukkah 013

1:
It is very easy to misunderstand our present mishnah. Indeed, it is a very good example of the kind of mishnah which cannot be correctly interpreted without the benefit of the Gemara and the traditional commentaries.

2:
One could easily suspect that "a building whose roof has opened" refers to a hut part of whose roof can be opened and closed at will. (Many moderns use such a hut for their sukkah.) But this is not at all what our mishnah is referring to! First of all the word building refers to a house, a place of regular abode. The roof of this house has not just 'opened' but has collapsed! In other words the roof of this building is open to the sky. (Obviously, in mishnaic times many houses of the middle and lower classes were badly constructed, "jerry built".)

3:
An enterprising householder faces a collapse of the roof of his house just before the festival of Sukkot. He decides to wait with the reconstruction of the roof and meanwhile to set his s^ekhakh above the walls so that his house becomes his sukkah. However, the opening that the collapse of the roof has created is far greater than the amount of s^ekhakh that he has. So he sets his s^ekhakh (upon slats) in the middle of what was the roof, leaving a space around it which is open to the sky. Our mishnah states that if the distance between the edge of the valid s^ekhakh to one or more of the panels (walls) of the sukkah is greater than 4 cubits (2 metres, say 5 feet) then the whole sukkah is invalid.

4:
The same would apply if only part of the roof had collapsed: provided that the part of the roof that still exists (between the s^ekhakh and the wall) is less than 4 cubits the sukkah is still valid.

5:
However, we must pay attention here to a different situation described by Rambam in his commentary on our mishnah. What the mishnah has stated only applies when the part of the roof not covered by s^ekhakh is open to the skies. If it is roofed in, even temporarily, the situation is different.

In other words, as long as there is valid s^ekhakh we can accept roofing with some substance that is invalid as s^ekhakh provided that the distance between the wall of the sukkah and the edge of the s^ekhakh is less than 4 cubits. We imagine, as it were, that the top of the panel has been bent inwards, towards the s^ekhakh. (Thus, anyone sitting under this part of the sukkah is still considered as sitting in a valid sukkah.)

6:
We have already described the nature of the 'courtyard'. (See sukkah 006.) Some of the more well-to-do courtyards would have an inner portico. This is a colonnade set a small distance from the face of the houses, creating a kind of passage, which is roofed over. A communal sukkah could be created by placing s^ekhakh over the area between the colonnades. But this area would be so large that sometimes there would not be enough s^ekhakh to cover the whole area thus created. Our mishnah explains that the same rule as applies to roofless house would apply in the case of a sukkah surrounded by a portico: a roof created from substances that are invalid as s^ekhakh can be created between the valid s^ekhakh and the portico provided that the distance is less than 4 cubits, as explained above.

7:
The last clause of our mishnah clarifies a point upon which we have already touched. If the distance between the valid s^ekhakh and the wall of the sukkah is greater than 4 cubits then we cannot consider what is left of the roof (which is invalid as s^ekhakh) as just part of a 'bent panel'. Anyone who sits under that part of the roof is not sitting in a valid sukkah.

8:
It is very interesting that even so careful and articulate a commentator as Rambam can sometimes write something that is erroneous simply out of habitual language. He writes:

We know that for a sukkah to be valid it only needs three walls, so 'all four sides' in Rambam's sentence is not quite accurate. He also describes a portico as a sidewalk or pavement, which is only partly correct.