Eruvin 46A

כל שכן דהוו להו נולד, דאסירי!

The Talmud raises a difficulty: If the water was previously not in its current state, all the more so should it be considered as something that came into being [nolad] on the Festival, and consequently it is prohibited to carry it. Something that came into being or assumed its present form on Shabbat or Festivals is considered set-aside [muktze] and may not be handled on Shabbat or Festivals.

אלא: מיא בעבים מינד ניידי. השתא דאתית להכי, אוקיינוס נמי לא ליקשו לך, מיא באוקיינוס נמי מינד ניידי, ותניא: נהרות המושכין ומעיינות הנובעין הרי הן כרגלי כל אדם.

Rather, we should say: The water in clouds is in constant motion and therefore does not acquire residence there. The Talmud comments: Now that you have arrived at this answer, the ocean should also not be difficult for you, as the water in the ocean is also in constant motion. And it was taught in a baraita: Flowing rivers and streaming springs are like the feet of all people, as their waters do not acquire residence in any particular place. The same law also applies to clouds and seas.

אמר רבי יעקב בר אידי אמר רבי יהושע בן לוי: הלכה כרבי יוחנן בן נורי. אמר ליה רבי זירא לרבי יעקב בר אידי: בפירוש שמיע לך או מכללא שמיע לך? אמר ליה: בפירוש שמיע לי.

R' Ya’akov bar Idi said that R' Yehoshua ben Levi said: The halakha is in accordance with the opinion of R' Yoḥanan ben Nuri, that one who was asleep at the beginning of Shabbat may travel 2,000 cubits in every direction. R' Zeira said to R' Ya’akov bar Idi: Did you hear this halakha explicitly from R' Yehoshua ben Levi, or did you understand it by inference from some other ruling that he issued? R' Ya’akov bar Idi said to him: I heard it explicitly from him.

מאי כללא? דאמר רבי יהושע בן לוי: הלכה כדברי המיקל בעירוב.

The Talmud asks: From what other teaching could this ruling be inferred? The Talmud explains: From that which R' Yehoshua ben Levi said: The halakha is in accordance with the lenient opinion with regard to an eiruv.