Gittin 27A

מתני׳ המביא גט ואבד הימנו; מצאו לאלתר ⁠– כשר, ואם לאו ⁠– פסול. מצאו בחפיסה או בדלוסקמא, אם מכירו ⁠– כשר.

Mishnah: With regard to an agent who brings a bill of divorce and it was lost from him, if he finds it immediately then the bill of divorce is valid. But if not, then it is invalid, as it is possible that the bill of divorce that he found is not the same one that he lost, and this second bill of divorce belongs to someone else whose name and wife’s name are identical to the names of the husband and wife in the lost bill of divorce. However, if he found it in a ḥafisa or in a deluskema that he knows is his, or if he recognizes the actual bill of divorce, then it is valid.

גמ׳ ורמינהו: מצא גיטי נשים ושחרורי עבדים, דייתיקי, מתנות ושוברין, הרי זה לא יחזיר ⁠– שאני אומר כתובין היו, ונמלך עליהן שלא ליתנן. הא אמר ״תנו״⁠ – נותנין; ואפילו לזמן מרובה!

Talmud: The Mishnah teaches that if a bill of divorce was lost before being received by the woman it is invalid unless it was found immediately. And the Talmud raises a contradiction from a Mishnah (Bava Metzia 18a): If one found bills of divorce, or bills of manumission, wills [dayetikei], deeds of gifts, or receipts, this finder should not return these items to the one who is presumed to have lost them, as I say it is possible that they were written and then the writer reconsidered about them and decided that he would not give them. One could infer from this Mishnah as follows: But if the writer said: Give these found documents to the intended recipient, one gives them, and this is true even if a long time passed since they were lost, and there is no concern that perhaps this document belongs to someone else with the same name.