Sukkah 17A

מתני׳ הרחיק את הסיכוך מן הדפנות שלשה טפחים ⁠— פסולה.

Mishnah: If one distanced the roofing from the walls of the sukka at a distance of 3 handbreadths the sukka is unfit, because 3 handbreadths of open space, even adjacent to the walls, render the sukka unfit.

בית שנפחת וסיכך על גביו ⁠— אם יש מן הכותל לסיכוך ארבע אמות, פסולה.

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 4 or more cubits of the remaining original roof, it is an unfit sukka. If the roofing is less than 4 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.

וכן חצר שהיא מוקפת אכסדרה, סוכה גדולה שהקיפוה בדבר שאין מסככין בו ⁠— אם יש תחתיו ארבע אמות, פסולה.

And likewise, in the case of a courtyard that is surrounded on 3 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 4 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 4 cubits beneath the unfit roofing, the sukka is unfit. The principle of curved wall does not apply to unfit roofing that measures 4 cubits or more.

גמ׳ כל הני למה לי? צריכא: דאי אשמעינן בית שנפחת ⁠— משום דהני מחיצות לבית עבידן. אבל חצר המוקפת אכסדרה, דמחיצות לאו לאכסדרה עבידי ⁠— אימא לא, צריכא.

Talmud: The Talmud asks: Why do I need all these cases based on the identical principle of curved wall? The Talmud explains: It is necessary to cite all the cases, as, if the Mishnah 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 3 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 Mishnah to cite that case as well.