Eiruvin 8:5-6

Eiruvin 8:5

If one of the residents of a courtyard went to go spend Shabbos in another town (and therefore did not participate in the eiruv), Rabbi Meir says the absent resident impedes the others’ ability to carry whether he is Jewish or non-Jewish; Rabbi Yehuda says that the absentee does not impede their ability. Rabbi Yosi says that a non-Jew impedes in such a circumstance but an absent Jew does not because one would not expect a Jew to return home on Shabbos. Rabbi Shimon says that even if a man went to spend Shabbos with his daughter elsewhere in the same town, he does not impede others’ ability to carry because he has already rejected the idea of returning.

Eiruvin 8:6

If there’s a pit of water between two courtyards, one may not draw from it on Shabbos unless they constructed a partition ten handbreadths high (about 30”) inside the pit, whether above the water, below the water or below the rim. Rabban Shimon ben Gamliel says that Beis Shammai require it below the water but that Beis Hillel permit it also above the water. Rabbi Yehuda says that the partition is unnecessary since the wall that separates the courtyards passes over the pit.