Siman - Eruvin Daf 44

  • Creating a human enclosure

On the bottom of Daf 43b the Gemara brought an incident when Nechemyah brei d’Rav Chanilai became engrossed in his learning and accidently went out of his techum. When he realized where he was, he stopped and remained within his dalet amos. When Rav Chisda told Rav Nachman, Nechemya’s Rebbe, Rav Nachman said, עשה לו מחיצה של בני אדם ויכנס – make a human partition for him by lining up people so that their bodies form an enclosure around him which reaches back into the techum and let him enter his original techum

Rava said it was obvious that the case was where there were not enough people to form an enclosure all the way back to the techum, and Rav Chisda wanted to know if the halachah follows Rebbe Eliezer who permits a person within two amos of his techum to return to it. If there had been enough people, there would be no question that it would be permissible since the halachah goes according to Rabban Gamliel who permits a person to move through an entire enclosed area even though the enclosure was not there at the start of Shabbos.

  • Using a person as a sukkah wall

Rav Nachman bar Yitzchak brought a Baraisa that taught that if a wall of a Sukkah fell on Yom Tov one is not permitted to station a person, animal or utensils in its place, לפי שאין עושין אהל עראי בתחילה ביום טוב ואין צריך לומר בשבת – because one may not make a temporary structure from start on Yom Tov and it goes without saying that he may not do so on Shabbos. Rava brought a Baraisa that seemingly disagrees and says, עושה אדם את חבירו דופן – a person may use his friend as a wall of a Sukkah, כדי שיאכל וישתה וישן – so that he may eat, drink and sleep in it.

The Gemara resolves the contradictions by saying that the first Baraisa involves someone who is aware that he is being used as a mechitzah which does not work. The second Baraisa involved someone who was not aware that he was being used as a mechitzah.

  • הבלעת תחומין מילתא היא

The next Mishnah states, מי שיצא ברשות – One who left his techum with reshus, for example for edus hachodesh, and was told that there was no longer any need for him to testify, has a new techum of two thousand amos in every direction. If he was told this while he was still in his original techum, it is as if he had never left. Rabbah explains that this means that it is as if he never left his house. The Gemara explains that since he uprooted himself from his techum by setting out to leave, one might have thought that his new techum is centered around him. The Mishnah is coming to teach therefore, that this is not so if he is still in his original techum. Rav Shimi bar Chiya says that it means that if the new techum overlaps with his original techum it is as if he never left his original techum. The Gemara clarifies that Rav Shimi bar Chiya holds, הבלעת תחומין מילתא היא – there is a halachic principle that the overlap of two techumim areas join the two areas into a single techum, and Rabbah disagrees with this rule.