Study Eruvin folio 77A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
ורבי יוחנן אמר: אלו מעלין מכאן ואוכלין, ואלו מעלין מכאן ואוכלין.
And R' Yoḥanan said: These residents of one courtyard may raise food from their courtyard to the top of the wall and eat it there, and they may lower the food from the wall to the courtyard; and those residents of the other courtyard may raise food from their courtyard and eat it there, and they may lower the food from the wall to the courtyard. This is because the wall is considered nonexistent, and its domain is viewed as part of the two courtyards.
תנן: אלו עולין מכאן ואוכלין, ואלו עולין מכאן ואוכלין. עולין — אין, מעלין — לא.
We learned in the Mishnah: If there was produce on top of the wall, these residents of one courtyard may ascend from this side and eat from it, and those residents of the other courtyard may ascend from that side and eat from it. The Talmud infers from this: To ascend, yes, it is permitted, but to raise food from the courtyard to the top of the wall, no, it is not permitted. This presents a challenge to R' Yoḥanan’s opinion.
הכי קאמר: יש בו ארבעה על ארבעה, עולין — אין, מעלין — לא. אין בו ארבעה על ארבעה — מעלין נמי.
The Talmud answers that this is what the Mishnah is saying: If the top of the wall between the two courtyards is 4 by 4 handbreadths, then to ascend, yes, it is permitted. However, to raise food, no, it is prohibited, because in that case the top of the wall is considered a domain in its own right. But if it is not 4 by 4 handbreadths, it is an exempt domain, and therefore they may raise their food onto the wall as well.