Gittin 64A

או אחד מן הראשונים, ואחד מן האחרונים, ואחד מצטרף עמהן.

or if there is one witness from the first pair of witnesses and one witness from the latter pair, and one additional witness joins with them as the second witness in both testimonies.

גמ׳ איתמר: בעל אומר לפקדון, ושליש אומר לגירושין ⁠– מי נאמן? רב הונא אמר: בעל נאמן, ורב חסדא אמר: שליש נאמן.

Talmud: It was stated that there is an amoraic dispute in a case where a husband says that he handed the bill of divorce to another as a deposit for safekeeping and not to deliver it to his wife, and that consequently she is not divorced, and the third party [shalish], to whom the husband gave the document, says that he was serving as an agent for receipt and the husband gave him the document for the purpose of divorce. In such a case, who is deemed credible? Rav Huna says: The husband is deemed credible, and Rav Ḥisda says: The third party is deemed credible.

רב הונא אמר: בעל נאמן ⁠– דאם איתא דלגירושין יהביה ניהליה, לדידה הוה יהיב לה ניהלה. ורב חסדא אמר: שליש נאמן ⁠– דהא הימניה.

The Talmud elaborates: Rav Huna said that the husband is deemed credible, as, if it is so that he gave it to the third party for the purpose of divorce, he would have given the bill of divorce directly to her. Both husband and wife are in the same city. Why did he give it to a third party? Apparently, he merely entrusted him with the bill of divorce for safekeeping. And Rav Ḥisda said: The third party is deemed credible, as the husband himself deemed him credible by entrusting him with the bill of divorce.

מתיב רבי אבא: הודאת בעל דין כמאה עדים דמי, ושליש נאמן משניהם. כיצד? זה אומר כך, וזה אומר כך, שליש נאמן!

R' Abba raises an objection to the opinion of Rav Huna from a baraita in the Tosefta (Bava Metzia 1:10): The legal status of the admission of a litigant is similar to that of the testimony of 100 witnesses, and the statement of a third party is deemed more credible than the statements of both of the litigants. How so? If this litigant, the creditor, says that the debtor owes him this sum, and that litigant, the debtor, says that he owes that lower sum, the third party to whom the debtor gave the money to pay the creditor is deemed credible to establish the sum of the debt. This contradicts the opinion of Rav Huna, who said that the husband, not the third party, is deemed credible.