Talmud - Eruvin 91a עירובין צ״א א׳

Similarly, enclosures are a domain in and of themselves, and one is therefore permitted to carry from one enclosure to another. According to the statement of the Rabbis, roofs and courtyards constitute one domain, and therefore, one may carry even from a roof to a courtyard; however, enclosures are one discrete domain. According to the statement of Rabbi Shimon, all of them, roofs, courtyards, and enclosures, are one domain, and therefore it is permitted to carry between any of them.

The Gemara comments: A baraita was taught in accordance with the opinion of Rav, and a baraita was taught in accordance with the opinion of Rav Yehuda. The Gemara elaborates. A baraita was taught in accordance with the opinion of Rav, that according to the Rabbis one may carry only four cubits on each roof: All the roofs of a city are one domain, and it is prohibited to carry objects up or carry them down, from the roofs to the courtyard or from the courtyard to the roofs. And with regard to vessels that were inside a courtyard when Shabbat began, it is permitted to carry them in the courtyard even if an eiruv was not established, and it is likewise permitted to carry them from that courtyard to other courtyards. With regard to vessels that were on the roofs when Shabbat began, it is permitted to carry them on the roofs, provided that one roof is neither ten handbreadths higher nor ten handbreadths lower than the other. This is the statement of Rabbi Meir. And the Rabbis say: Each and every one of the roofs is a domain in and of itself, and one may move objects on each roof only within four cubits.

Likewise, a baraita was taught in accordance with Rav Yehuda’s interpretation of the opinion of Rabbi Shimon. Rabbi Yehuda HaNasi said: When we were studying Torah with Rabbi Shimon in Tekoa, we would carry oil for smearing and a towel for drying from roof to roof, and from roof to courtyard, and from courtyard to courtyard, and from courtyard to enclosure, and from enclosure to enclosure, to refrain from carrying in a prohibited place, until we reached the spring in which we would bathe.

And similarly, Rabbi Yehuda said: There was an incident during a time of danger, when decrees were issued that banned religious observance, and we would carry a Torah scroll from courtyard to roof, and from roof to courtyard, and from courtyard to enclosure, to read from it.

The Sages said to him: The halakha cannot be determined from that incident, as an incident occurring during a time of danger is no proof. At a time of danger it is permitted to carry even in places where carrying is ordinarily prohibited by rabbinic law.

Rabbi Shimon says: Roofs, courtyards, and enclosures are all one domain with regard to vessels that were inside them when Shabbat began, and one may therefore carry from one of these areas to the other. However, they are not one domain with regard to vessels that were inside the house when Shabbat began.

Rav said: The halakha is in accordance with the opinion of Rabbi Shimon, provided that the residents of each courtyard did not establish a separate eiruv for themselves, as in that case they may not move objects from their houses into the courtyard. However, if they established a separate eiruv for each courtyard, without establishing an eiruv between the various courtyards, no, that is not the halakha, as we issue a decree lest one come to take out vessels from one of the houses to the courtyard, an action that is fundamentally permitted, and subsequently proceed to carry them out to a different courtyard with which an eiruv had not been established, which everyone agrees is prohibited.

And Shmuel said: The halakha is in accordance with Rabbi Shimon, whether they established an eiruv or whether they did not establish an eiruv. And similarly, Rabbi Yoḥanan said: Who whispered to you, who told you that there is a difference whether they established an eiruv or whether they did not establish an eiruv?

Rav Ḥisda strongly objects to this ruling. According to Shmuel and according to Rabbi Yoḥanan, people will say with regard to two vessels located in the same courtyard, one of which was in the courtyard when Shabbat began while the other was in the house, that moving this one, which was in the courtyard at the start of Shabbat, to another courtyard is permitted, while moving that one, which was in the house at the start of Shabbat, to another courtyard, is prohibited.

The Gemara answers: In this regard, Rabbi Shimon conforms to his standard reasoning, as he did not issue a decree due to these concerns. As we learned in a mishna, Rabbi Shimon said: To what is this matter comparable? It is comparable to three courtyards that are open into each other, and that are also open into a public domain. If the two outer courtyards each established an eiruv with the middle one, it is permitted for the residents of the middle one to carry into the two outer ones, and they, the residents of the two outer ones, are permitted to carry into it, but for the residents of the two outer courtyards it is prohibited to carry into each other, as they did not establish an eiruv together.

And in that case Rabbi Shimon did not issue a decree prohibiting one to carry objects from the middle courtyard to one of the outer ones lest one come to take out vessels from this outer courtyard to that outer courtyard, despite the fact that both sets of vessels are located in the middle courtyard. Here too, we do not issue a decree lest one come to take out utensils from one of the houses to the courtyard, and carry them to a different courtyard.

Rav Sheshet raised an objection. We learned in the mishna that Rabbi Shimon says: Roofs, courtyards, and enclosures are all one domain with regard to vessels that were inside them when Shabbat began. But they are not one domain with regard to vessels that were inside the house when Shabbat began. Granted, if you say that it is dealing with a case where the residents of the courtyards established an eiruv, that is how you find vessels that were taken from the house in the courtyard. Because those vessels were in the house at the beginning of Shabbat, they may not be moved to a different courtyard.

However, if you say it is referring to a case where they did not establish an eiruv, under what circumstances can the case of vessels from the house in the courtyard be found? This poses a difficulty for Rav. Rav Sheshet raised the objection, and he resolved it: It refers to the case of a hat or a shawl, which one wore in the house and subsequently went out to the courtyard and placed it there. In this manner, it is possible that objects taken from the house can be found in the courtyard, even if an eiruv was not established.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Eruvin 91a explores rabbinic disputes over carrying objects between roofs, courtyards, and enclosures on Shabbat, citing conflicting baraitot on domain boundaries.