MISHNA: If one distanced the roofing from the walls of the sukka at a distance of three handbreadths the sukka is unfit, because three handbreadths of open space, even adjacent to the walls, render the sukka unfit.

In the case of a house that was breached, creating a hole in the middle of the roof, and one roofed over the breach, if from the wall to the roofing there are four or more cubits of the remaining original roof, it is an unfit sukka. If the roofing is less than four cubits from the wall, the sukka is fit, based on the principle of curved wall; the remaining intact ceiling is considered an extension of the vertical wall.

And likewise, in the case of a courtyard that is surrounded on three sides by a portico, which has a roof but no walls, if one placed roofing over the courtyard between the different sides of the portico and the roof of the portico is four cubits wide, the sukka is unfit. Similarly, a large sukka that was surrounded at the edge of its roofing with material with which one may not roof a sukka, e.g., vessels susceptible to ritual impurity, if there are four cubits beneath the unfit roofing, the sukka is unfit. The principle of curved wall does not apply to unfit roofing that measures four cubits or more.

GEMARA: The Gemara asks: Why do I need all these cases based on the identical principle of curved wall? The Gemara explains: It is necessary to cite all the cases, as, if the mishna had taught us only the case of the house that was breached, I would have said that the principle of curved wall applies there because those walls were established for the house. Therefore, when the house is transformed into a sukka, the walls continue to serve their original function as walls of the sukka. However, with regard to a courtyard surrounded on each of the three sides by a portico, where its walls were established not for the portico but for the house that opens into the portico, and they happen to serve as the interior walls of the portico, I could say no, they are not considered as connected to the roofing at all. Consequently, it is necessary for the mishna to cite that case as well.

And if the mishna taught us only these two cases, one would have said that the principle of curved wall can apply because all of their roofing is fit roofing, and the preexisting roof of the house and the portico is unfit only due to the principle: Prepare it, and not from that which has already been prepared. However, here, in the case of a large sukka that was surrounded at the edge of its roofing with material with which one may not roof a sukka, where some of its roofing is unfit and the fit roofing does not actually reach the wall, one could say no, the roofing is unfit. Therefore, it is necessary to state that case as well.

§ Rabba said: I found the Sages of the school of Rav, who were sitting and saying in the name of Rav: Space without roofing renders the sukka unfit with a measure of three handbreadths of space. However, unfit roofing renders the sukka unfit with a measure of four handbreadths.

And I said to them: From where do you derive that space renders the sukka unfit when it amounts to three handbreadths? It is as we learned in the mishna: If one distanced the roofing from the walls of the sukka at a distance of three handbreadths, the sukka is unfit. If, indeed, this mishna is the source of the halakha, also in the case of unfit roofing, let it render the sukka unfit only if the roofing measures four cubits, as we learned in the same mishna: With regard to a house that was breached and one roofed over the breach, if from the wall to the roofing there is four or more cubits of the remaining original roof, the sukka is unfit.

And they said to me: Cite proof from the mishna, apart from this case, as both Rav and Shmuel said that in this case, the Sages in the mishna touched upon the principle of curved wall. In other words, the fact that this house is a fit sukka is unrelated to the minimum measure of unfit roofing. It is fit due to the principle of curved wall.

And I said to them: What if there is a sukka with less than four handbreadths of unfit roofing and an adjacent space of less than three handbreadths; what would be the status of the sukka? The sukka would be fit, since it lacks the minimum measure of both space and unfit roofing that renders a sukka unfit. If one then filled the space with skewers, what would be the status of the sukka? It would be unfit, as there would be more than four handbreadths of unfit roofing. But shouldn’t space, which is more stringent, as it renders the sukka unfit with only three handbreadths, be as stringent as unfit roofing, which renders the sukka unfit only with four handbreadths of unfit roofing?

And they said to me: If so, according to you, who said that unfit roofing renders a sukka unfit only with four cubits of unfit roofing, the same question arises. Just as, if there were a sukka with less than four cubits of unfit roofing and an adjacent space measuring less than three handbreadths, what would be its status? It would be fit. If one then filled the space with skewers, what would be its status? It would be unfit. Here too, the question arises: Shouldn’t space, which is more stringent, as it renders the sukka unfit with only three handbreadths of space, be as stringent as unfit roofing, which renders the sukka unfit with only four cubits of unfit roofing?

And I said to them: What is this comparison? Granted, according to my opinion, that I say that the measure of unfit roofing that renders a sukka unfit is four cubits,