Bava Metzia 24B

ואיבעית אימא: לעולם רבנן, מי קתני ״הן שלו״? ״אינו חייב להכריז״ קתני. ויניח, וייתי ישראל ויהיב ביה סימנא ושקיל.

And if you wish, say instead that actually the Mishnah is in accordance with the opinion of the Rabbis. Is it taught in the Mishnah that the items are his? It is taught that he is not obligated to proclaim his find. He may not keep them, but he should place the items in his possession and a Jew will come and provide a distinguishing mark to describe the items and take them.

תא שמע, דאמר רב אסי: מצא חבית יין בעיר שרובה גוים ⁠– מותרת משום מציאה ואסורה בהנאה. בא ישראל ונתן בה סימן ⁠– מותרת בשתיה, למוצאה.

Come and hear a proof from that which Rav Asi says: If one found a jug of wine in a city whose population has a majority of non-Jews, keeping the jug is permitted in terms of the halakhot of finding lost items because it presumably belonged to a non-Jew, and deriving benefit from the wine is prohibited, as it is presumed to be wine of a non-Jew. If a Jew came and provided a distinguishing mark to describe it, drinking the wine is permitted for its finder, as it proved to be the wine of a Jew. Nevertheless, it belongs to the finder, because the owner despaired of recovering a jug misplaced in a public area.

כמאן? כרבי שמעון בן אלעזר. שמע מינה כי קאמר רבי שמעון בן אלעזר ⁠– ברוב גוים אבל ברוב ישראל לא. לעולם אימא לך רבי שמעון בן אלעזר אפילו ברוב ישראל נמי קאמר, ורב אסי סבר לה כוותיה בחדא, ופליג עליה בחדא.

The Talmud explains the proof: In accordance with whose opinion is this statement of Rav Asi? It is in accordance with the opinion of R' Shimon ben Elazar. Conclude from it that when R' Shimon ben Elazar stated his opinion, it was only with regard to a place where there is a majority of non-Jews; but in a place where there is a majority of Jews, the owner does not despair of recovering his lost item. The Talmud rejects the proof: Actually, I will say to you that even with regard to a place where there is a majority of Jews, R' Shimon ben Elazar also stated his opinion, and Rav Asi holds in accordance with the opinion of R' Shimon ben Elazar in one case, that of a place where there is a majority of non-Jews, and disagrees with him in one case, that of a place where there is a majority of Jews.