Gittin 4B

והני גמירי; ומר סבר לפי שאין עדים מצויין לקיימו, והני נמי לא שכיחי?

and these people are learned with regard to this halakha, as a bill of divorce sent from Eretz Yisrael was certainly written in the correct manner. And one Sage, the Rabbis, holds: The reason for the testimony is because there are no witnesses available to ratify it, and these witnesses who travel from Eretz Yisrael overseas are also not frequently available.

רבה מתרץ לטעמיה, ורבא מתרץ לטעמיה. רבה מתרץ לטעמיה: דכולי עלמא לפי שאין בקיאין לשמה, והכא בגזירת מוליך אטו מביא קמיפלגי –

The Talmud again rejects the suggestion: One cannot prove that this issue is a dispute of the tanna’im, as Rabba resolves the different opinions in the Mishnah according to his line of reasoning, and Rava resolves them according to his line of reasoning. Rabba resolves them according to his line of reasoning, as follows: It may be that everyone agrees that the reason is because they are not experts in writing a bill of divorce for her sake, and here they disagree with regard to a decree applied in the case of one who delivers a bill of divorce to Eretz Yisrael due to the concern that it will be confused with the case of one who brings a bill of divorce from Eretz Yisrael.

דתנא קמא סבר: לא גזרינן מוליך אטו מביא.

The Talmud explains that the first tanna holds: The rabbis do not decree with regard to one who delivers due to one who brings. In other words, although one who delivers a bill of divorce from overseas to Eretz Yisrael must say: It was written in my presence and it was signed in my presence, one who brings a bill of divorce from Eretz Yisrael to a country overseas need not state this declaration.