לפי שאין בקיאין לשמה
It is because the people who live overseas are not experts in writing a bill of divorce for her sake. It is not sufficient for a bill of divorce to be written in a technically correct manner. It must also be written for the sake of the man and the woman who are divorcing. Therefore, when the witness comes before the court and says that it was written and signed in his presence, he is testifying that the writing and the signing of the bill of divorce were performed for the sake of the man and woman in question.
רבא אמר לפי שאין עדים מצויין לקיימו
Rava says a different reason: It is because there are no witnesses available to ratify it. Since the bill of divorce was written in a distant place, it is possible that the husband, or someone else, might later claim that the bill of divorce is a forgery. For this reason the agent must say that the bill of divorce was written and signed in his presence, a declaration that bars any subsequent objection on the part of the husband.
מאי בינייהו איכא בינייהו דאתיוהו בי תרי אי נמי ממדינה למדינה בארץ ישראל
The Gemara asks: What is the difference between these two explanations? The Gemara answers: There is a difference between them with regard to a case where two people brought the bill of divorce. In this case, two witnesses are available to ratify the bill of divorce if someone objects to its validity. Alternatively, the difference concerns a case where the agent brings the bill of divorce from one region to another region within Eretz Yisrael. Here there is no concern that the bill of divorce might not have been written for her sake, as the residents of Eretz Yisrael are aware of this requirement. However, witnesses are not necessarily available to confirm the document.
אי נמי באותה מדינה במדינת הים
Alternatively, there is a difference between the two explanations in a case where the agent brings the bill of divorce within that same region in a country overseas. According to the opinion of Rabba, who says the concern is that the people there might not know that the document must be written for her sake, this problem is equally relevant in this case. However, according to the opinion of Rava, who says that the reason is because witnesses are not available, if the bill of divorce is brought in the same region then the witnesses will be available to ratify it.
ולרבה דאמר לפי שאין בקיאין לשמה ליבעי תרי מידי דהוה אכל עדיות שבתורה עד אחד נאמן באיסורין
The Gemara asks: And according to the opinion of Rabba, who said that the reason is because they are not experts in writing a bill of divorce for her sake, let us require two witnesses to testify about this, just as is the case with regard to all testimonies in the Torah. The Gemara answers: One witness is deemed credible with regard to prohibitions. In other words, if there is uncertainty as to whether a matter is prohibited or permitted, in the case of the heretofore married woman, the testimony of one witnesses is sufficient.
אימור דאמרינן עד אחד נאמן באיסורין כגון חתיכה ספק של חלב ספק של שומן דלא איתחזק איסורא
The Gemara asks: One can say that we say one witness is deemed credible with regard to prohibitions in a case such as where there is a piece of fat, and it is uncertain if it is forbidden fat [ḥelev] and uncertain if it is permitted fat. In this situation the piece can be rendered permitted by a single witness, as there is no presumption that it is forbidden. Therefore, as there is an uncertainty, and one witness said it is permitted fat, he is deemed credible.
אבל הכא דאיתחזק איסורא דאשת איש הוי דבר שבערוה ואין דבר שבערוה פחות משנים
However, here, where there is a presumption that this woman is forbidden, as she is a married woman, a status she retains until it is established that she has received a bill of divorce, if so, this is a matter of forbidden sexual relations, and the general principle is that there is no matter of testimony for forbidden sexual relations that can be attested to by fewer than two witnesses.
רוב בקיאין הן ואפילו לר"מ דחייש למיעוטא סתם ספרי דדייני מיגמר גמירי ורבנן הוא דאצרוך והכא
The Gemara answers: Rabba’s concern is not equivalent to a case of uncertainty, as most Jewish people are experts in the requirement that a bill of divorce must be written for the woman’s sake. And this is so even according to the opinion of Rabbi Meir, who is generally concerned about a minority in a matter of forbidden sexual relations. In this case Rabbi Meir concedes that one need not be concerned for the minority, as ordinary judicial scribes, who write bills of divorce, are learned in this halakha, and know that a bill of divorce must be written for the woman’s sake. And it is the Sages who required testimony about this matter, as an extra precaution. And here, with regard to this testimony,