Gittin 16B

כשר. אלמא קסבר שנים שהביאו גט ממדינת הים, אין צריכין שיאמרו: ״בפנינו נכתב ובפנינו נחתם״.

it is valid. The Talmud comments: Apparently, R' Yoḥanan holds that two people who brought a bill of divorce from a country overseas are not required to say: It was written in our presence and it was signed in our presence.

אמר ליה אביי: אלא מעתה, סיפא דקתני: שנים אומרים ״בפנינו נכתב״ ואחד אומר ״בפני נחתם״⁠ – פסול, ורבי יהודה מכשיר;

Abaye said to Rav Shmuel bar Yehuda: If that is so, if the Mishnah is referring specifically to a case where the document was not produced by both of them, consider the latter clause of the Mishnah, which teaches: If two people say: It was written in our presence, and one person says: It was signed in my presence, it is invalid, and R' Yehuda deems it valid.

טעמא דאין הגט יוצא מתחת ידי שניהם, הא גט יוצא מתחת ידי שניהם ⁠– מכשרי רבנן?! אמר ליה: אין.

The Talmud infers: The reason this document is invalid is specifically due to the fact that the bill of divorce was not produced by both of them, but if the bill of divorce was produced by both of them would the Rabbis deem it valid? Rav Shmuel bar Yehuda said to Abaye: Yes, the Rabbis would deem this bill of divorce valid.

וכי אין גט יוצא מתחת ידי שניהם במאי פליגי? מר סבר: גזרינן דלמא אתיא לאיחלופי בקיום שטרות דעלמא ⁠– בעד אחד; ומר סבר: לא גזרינן.

The Talmud asks: And in a case where the bill of divorce was not produced by both of them, with regard to what underlying principle do they disagree? The Talmud explains: One Sage, the Rabbis, holds: The rabbis decree that it is invalid lest people will come to confuse this case with the typical situation of ratification of legal documents. In other words, they will think it is possible to ratify other documents by the testimony of one witness. And one Sage, R' Yehuda, holds that the rabbis do not decree that it is invalid for this reason.