Sukkah 22B

פחות מארבעה ⁠— אין צריך להביא קורה אחרת, ארבעה ⁠— צריך להביא קורה אחרת.

If there is a gap of less than 4 handbreadths, one need not bring another cross beam. However, if there is a gap of 4 handbreadths, one must bring another cross beam.

וכן שתי קורות המתאימות, לא בזו כדי לקבל אריח ולא בזו כדי לקבל אריח, אם מקבלות אריח לרחבו טפח ⁠— אין צריך להביא קורה אחרת, ואם לאו ⁠— צריך להביא קורה אחרת,

And similarly, if two parallel, extremely narrow cross beams are placed alongside each other, even though there is not sufficient width in this beam in order to receive and support a small brick, and there is not sufficient width in that beam in order to receive and support a small brick, if the two beams together can receive a small brick along its handbreadth width, one need not bring another cross beam to render the alleyway fit for one to carry within it. But if not, one is required to bring another cross beam.

רבן שמעון בן גמליאל אומר: אם מקבלות אריח לארכו שלשה טפחים ⁠— אין צריך להביא קורה אחרת. ואם לאו ⁠— צריך להביא קורה אחרת.

Rabban Shimon ben Gamliel says: If the two cross beams can receive a small brick along its length, which is 3 handbreadths, one need not bring another cross beam, but if not, one must bring another cross beam.

היו אחת למעלה ואחת למטה, רבי יוסי ברבי יהודה אומר: רואין העליונה כאילו היא למטה, ואת התחתונה כאילו היא למעלה. ובלבד שלא תהא עליונה למעלה מעשרים אמה, והתחתונה למטה מעשרה. הא זה וזה בתוך עשרים ⁠— אמרינן חבוט רמי אף על גב דלית ביה טפח!

R' Yosei, son of R' Yehuda, says: If these two narrow cross beams are placed at different heights, one above and one below, one considers the upper one as though it were below, and the lower one as though it were above, i.e., close together. If the two together are capable of supporting a small brick, they render the alleyway fit for one to carry within it, although they are not actually close to each other, provided that the upper cross beam is not above 20 cubits off the ground and the lower one is not below 10 handbreadths off the ground, between which a cross beam renders an alleyway fit for one to carry within it. By inference, if both this beam and that beam are within 20 cubits, we say that the principle: Lower and cast the upper beam down even though there is not the width of a handbreadth in the upper beam. This is difficult according to Rava’s opinion, as he holds that the principle: Lower and cast, does not apply when the width of the upper crossbeam is less than a handbreadth.