Eruvin 17A

רישא רבי יוסי ברבי יהודה וסיפא רבנן?!

The Talmud asks: Is that to say that the first clause of Rav Naḥman’s ruling is in accordance with the opinion of R' Yosei, son of R' Yehuda, and the latter clause is in accordance with the opinion of the Rabbis?

אין, משום דקאי אבוה בשיטתיה.

The Talmud answers: Yes, because his father, R' Yehuda, holds in accordance with his opinion with regard to areas enclosed for the sake of an individual. This being the case, their opinion on this matter is that of the many.

אמר רב גידל אמר רב: שלשה בחמש ⁠— אסורין, בשבע מותרין. אמרו ליה: אמר רב הכי? אמר להו: אורייתא נביאי וכתיבי דאמר רב הכי!

Rav Giddel said that Rav said: At times, for 3 people it is prohibited to carry even in an area of 5 beit se’a; at times, it is permitted for them to carry even in an area of 7 beit se’a. These statements appear irreconcilable, and his colleagues said to him: Did Rav actually say that? He said to them: I swear by the Torah, the Prophets, and the Writings, that Rav said so.

אמר רב אשי: מאי קשיא? דילמא הכי קאמר: הוצרכו לשש והקיפו בשבע ⁠— אפילו בשבע מותרין. לא הוצרכו אלא לחמש והקיפו בשבע ⁠— אפילו בחמש אסורין.

Rav Ashi said: What is the difficulty here? Perhaps this is what he is saying: If they needed 6 beit se’a, and they enclosed 7, they are permitted to carry even in all 7, as one empty beit se’a does not render it prohibited for one to carry in the rest of the area. If, however, they needed only 5 beit se’a, and they enclosed 7, carrying even in 5 is prohibited, as there is an unoccupied space of two beit se’a.

ואלא הא דקתני: ״ובלבד שלא יהא בית סאתים פנוי״⁠ — מאי לאו, פנוי מאדם? לא, פנוי מכלים.

The Talmud asks: However, with regard to that which the baraita is teaching, that the partition renders the area fit for one to carry within it provided that there will not be an unoccupied space of two beit se’a, what, is it not in fact referring to space unoccupied by people? In other words, isn’t the baraita teaching that the enclosed area may not be two beit se’a larger than a measure of two beit se’a per person? Accordingly, if 3 people enclosed an area of 7 beit se’a, it should always be permitted for them to carry there, as they are entitled to 6 beit se’a and only one beit se’a is unoccupied. The Talmud answers: No, it means unoccupied by utensils. Although they would be entitled to 6 beit se’a if needed, since they need only 5 in practice and a space of two beit se’a remains unoccupied, the effectiveness of the partitions is negated and carrying therein is prohibited.