Bava Metzia 21B

יאוש שלא מדעת, אביי אמר: לא הוי יאוש. ורבא אמר: הוי יאוש.

With regard to one’s despair of recovering his lost item that is not a conscious feeling, i.e., were he aware of the loss of his property, he would have despaired of its recovery, but he was unaware of his loss when the finder discovered the item, Abaye said: It is not considered despair; the owner maintains ownership of the item, and the finder may not keep it. And Rava said: It is considered despair and the finder may keep it.

בדבר שיש בו סימן ⁠– כולי עלמא לא פליגי דלא הוי יאוש. ואף על גב דשמעיניה דמיאש לסוף, לא הוי יאוש, דכי אתא לידיה ⁠– באיסורא הוא דאתא לידיה, דלכי ידע דנפל מיניה לא מיאש, מימר אמר: סימנא אית לי בגויה, יהבנא סימנא ושקילנא ליה.

The Talmud limits the scope of the dispute. In the case of an item on which there is a distinguishing mark, everyone agrees that despair that is not conscious is not considered despair. And even though we hear that he ultimately despairs of recovering the item, it is not considered despair, as when the item came into the possession of the finder, it was in a prohibited manner that it came into his possession. It is prohibited because when the owner learns that it fell from his possession, he does not despair of its recovery immediately. Instead, he says: I have a distinguishing mark on the item; I will provide the distinguishing mark to the finder, and I will take it.

בזוטו של ים ובשלוליתו של נהר, אף על גב דאית ביה סימן, רחמנא שרייה, כדבעינן למימר לקמן.

With regard to an item swept away by the tide of the sea or by the flooding of a river, even though the item has a distinguishing mark, God permits the finder to keep it as we seek to state below, later in the discussion.

כי פליגי בדבר שאין בו סימן. אביי אמר: לא הוי יאוש, דהא לא ידע דנפל מיניה. רבא אמר: הוי יאוש, דלכי ידע דנפל מיניה ⁠– מיאש. מימר אמר: סימנא לית לי בגויה, מהשתא הוא דמיאש.

When they disagree, it is with regard to an item in which there is no distinguishing mark. Abaye said: Despair that is not conscious is not considered despair, as he did not know that the item fell from him; therefore, he cannot despair of recovering it. Rava said: Despair that is not conscious is considered despair, as when he discovers that it fell from him, he will despair of its recovery; as he says upon this discovery: I have no distinguishing mark on the item. Therefore, it is considered from now, when the item fell, that he despairs.