Kiddushin 3:8 - 3:9

וגרשתיה – I received her Jewish bill of divorce.

והרי היא קטנה – now when I said this about her.

נאמן – to make her disqualified from the priesthood [through marriage]. He is believed about his daughter all the time that she is a minor, as it is written (Deuteronomy 22:16): “[And the girl’s father shall say to the elders,] ‘I gave this man my daughter to wife…” When he said “[this] man, he prohibited her to everyone else, for we do not know to whom [it was that he was talking about], and when he returned and said to this one, he made her permissible to him.

והרי היא גדולה – and if he said this after she had grown [into adulthood], but did not say this when she was still a minor, he is not believed.

נשבית ופדיתיה וכו' אינו נאמן – to disqualify her from the priesthood, for regarding marriage, the All-Merciful (i.e., the Torah) believes the father; regarding her being taken captive, he is not believed.

יש לי בנים – and my wife will not be dependent upon her brother-in-law (who in the case of his brother dying without issue enters into his estate and marries his wife).

יש לי אחים – and my wife will be dependent upon her brother-in-law, but up until now, she was in the status that she would not be dependent.

אין הבוגרות בכלל – because they are not in the domain of the father to become betrothed, and even though he had made the adult daughter an agent to receive her betrothal, we say (Kiddushin 64b) that a person does not put aside a Mitzvah which [primarily] rests on him [to see to the betrothal of his daughter] and perform one which is not incumbent upon him [concerning his adult daughter]. But minors and girls between the ages of twelve and twelve-and-one-half require a Jewish bill of divorce, out of doubt, for we don’t know which of them he (i.e., the father) had betrothed.

קדשתי את בתי גדולה – it was necessary for the Tanna [of our Mishnah] to teach us of the dispute of Rabbi Meir and Rabbi Yosi in the case of: “I betrothed the eldest” and “I betrothed the youngest.” For had [the Mishnah] only taught us regarding “I betrothed the eldest,” I would think that on this which Rabbi Meir is commenting upon, and since there is a younger [daughter] than her, it is to this one, “the elder” that he calls her, for it is praiseworthy for a person to call his daughter with the language of “older” even though she is “younger,” when there is younger sister younger than her. But, regarding a minor, I would say that he (i.e., Rabbi Meir) would agree with Rabbi Yosi, that all the while that he can call her “elder,” he would not call her “younger.” But if [the Mishnah only taught] that alone (i.e., the statement of Rabbi Meir), it is on that alone which Rabbi Meir is commenting upon but on this one (“I betrothed the younger”), I would say that Rabbi Yosi agrees with Rabbi Meir. Therefore, it was necessary to teach both of them. And the Halakha is according to Rabbi Yosi in both cases.