Commentary for Kiddushin 128:19

The baraita refers to a situation where we thought he had brothers but not sons (making her liable for yibbum). If he is lying in order to exempt her from yibbum, we could ask why he would tell such a lie. He could, after all, just divorce her right before his death and thereby exempt her. Therefore, he is believed to exempt her from yibbum.
Rabbi [Judah Hanasi] would hold that when he said he has no brothers at the time of his kiddushin, he is totally believed, because why would he lie. This overrides the presumption that he had no sons, and now exempts her from yibbum. He will then not be believed later to contradict his words by saying that he does have brothers.
Rabbi Natan says that “why would I lie” is considered like a presumption and one presumption cannot cancel out another. So he was not believed to say he had no brothers at the time of his kiddushin. At the time of kiddushin we maintain that he has brothers and no sons and he cannot later contradict himself at the time of his death by saying either that he has no brothers or that he has sons.

The baraita refers to a situation where we thought he had brothers but not sons (making her liable for yibbum). If he is lying in order to exempt her from yibbum, we could ask why he would tell such a lie. He could, after all, just divorce her right before his death and thereby exempt her. Therefore, he is believed to exempt her from yibbum.
Rabbi [Judah Hanasi] would hold that when he said he has no brothers at the time of his kiddushin, he is totally believed, because why would he lie. This overrides the presumption that he had no sons, and now exempts her from yibbum. He will then not be believed later to contradict his words by saying that he does have brothers.
Rabbi Natan says that “why would I lie” is considered like a presumption and one presumption cannot cancel out another. So he was not believed to say he had no brothers at the time of his kiddushin. At the time of kiddushin we maintain that he has brothers and no sons and he cannot later contradict himself at the time of his death by saying either that he has no brothers or that he has sons.

This section connects back to the previous mishnah as well as to the next section. If a father states that he betrothed one of his daughters, but does not remember which one he betrothed, all of his minor daughters are in a state of possible betrothal, since he has the legal right to betroth any of them. None of them can marry until the matter is clarified. However, the girls who are of majority age are not doubtfully betrothed since the father has no legal right to betroth them.

The father says he has given in betrothal his “eldest daughter” to a man, and he has forgotten who that man is, and the question is who his “eldest daughter” is? Once we figure out whom the eldest daughter is that daughter will be forbidden to marry any other man, and his other daughters will be permitted. Again, the man has two sets of daughters; one set is a group of “seniors” in that they are all older than the other set which are “juniors.” According to Rabbi Meir, any daughter who has a younger sister may be called the “eldest daughter” since she is older than another daughter. The only daughter who cannot possibly be called the “eldest daughter” is the youngest daughter of the youngest set.
Rabbi Yose rules that only the eldest daughter of the seniors is called the “eldest daughter” and therefore only she is prohibited.

This section is basically the same as the previous section, except that in this section the father claims that he gave his “youngest daughter” in betrothal. The opinions of Rabbi Meir and Rabbi Yose are consistent with those above.

When a man says “I betrothed my daughter” without specifying which, he cannot be referring to his daughter who is a bogeret, but he can be referring to his minor daughter. But this implies that all of his minor daughters are impacted by his statement, even though, if he has more than one, this is a case of “kiddushin that cannot be followed by intercourse” because any one girl could be his wife’s sister. Thus we could learn that in such cases the kiddushin is at least doubtfully valid—each minor daughter is doubtfully betrothed. To recall, this was a major topic discussed earlier in the tractate and thus we do not want this mishnah to answer the question.
The Talmud answers that there was only one minor. Thus there is no doubt that she is the one who is betrothed.

When a man says “I betrothed my daughter” without specifying which, he cannot be referring to his daughter who is a bogeret, but he can be referring to his minor daughter. But this implies that all of his minor daughters are impacted by his statement, even though, if he has more than one, this is a case of “kiddushin that cannot be followed by intercourse” because any one girl could be his wife’s sister. Thus we could learn that in such cases the kiddushin is at least doubtfully valid—each minor daughter is doubtfully betrothed. To recall, this was a major topic discussed earlier in the tractate and thus we do not want this mishnah to answer the question.
The Talmud answers that there was only one minor. Thus there is no doubt that she is the one who is betrothed.

The mishnah did not mean that there was more than one bogeret, such that by implication there would also be more than one minor daughter. It only meant “bogrot” in general, meaning any daughter who fits into that category.

A father cannot marry off his daughter once she is a bogeret, a girl of majority age. So this mishnah is too obvious—obviously the bogeret cannot be the girl who is betrothed.
To make the mishnah less obvious (and therefore not extraneous) the Talmud suggests that this was a case where the bogeret appointed her father to accept her kiddushin on her behalf. The mishnah rules that if the father does not remember which girl he betrothed, we can assume that he did not betroth the bogeret. The assumption is that since if he marries off his younger daughters, he would receive the betrothal money, he must have married off one of them and not the older daughter who appointed him as an agent.

Even if the bogeret says that the father can keep the kiddushin money, we still assume he married off the younger daughter because marrying her off is his responsibility, whereas marrying off the bogeret is not his responsibility.

According to this logic, a father prefers to call his daughters “elder.” So if we had learned only the first clause, we might have thought that R. Meir disagrees with R. Yose only in this case and says that eldest could refer to any except the youngest. But if he says “youngest” we might have thought that he agrees with R. Yose and that this term can only refer to the youngest. Therefore, we need the second clause.

According to this logic, a father prefers to call his daughters “elder.” So if we had learned only the first clause, we might have thought that R. Meir disagrees with R. Yose only in this case and says that eldest could refer to any except the youngest. But if he says “youngest” we might have thought that he agrees with R. Yose and that this term can only refer to the youngest. Therefore, we need the second clause.

If we did not have the first clause I might have thought that R. Yose disagrees only in this case. Youngest can only refer to the youngest daughter of all. But in the first case, I might have thought that he agrees with R. Meir, that “eldest” could refer to any except the very youngest.
Therefore, we need both disputes to let you know that they dispute in both cases.

In our mishnah R. Meir seems to say that people will make statements that cause doubts to arise. Such is the man who says “I have given in betrothal my eldest daughter, but I do not know whether the eldest of the seniors or the eldest of the juniors, or the youngest of the seniors who is older than the eldest of the juniors.” R. Yose says that there is no doubt that this statement refers to the oldest daughter. A person does not make a statement that cause a doubt to arise. Therefore we interpret his statement in accordance.
But in another mishnah from Nedarim the two tannaim disagree over the meaning of “Until pene’ Pesah.” R. Meir seems to be certain of this statement’s meaning—it means before Pesah begins. But R. Yose seems to think it is doubtful—maybe it means until Pesah is over in which case his vow is effective until Pesah is over.

In our mishnah R. Meir seems to say that people will make statements that cause doubts to arise. Such is the man who says “I have given in betrothal my eldest daughter, but I do not know whether the eldest of the seniors or the eldest of the juniors, or the youngest of the seniors who is older than the eldest of the juniors.” R. Yose says that there is no doubt that this statement refers to the oldest daughter. A person does not make a statement that cause a doubt to arise. Therefore we interpret his statement in accordance.
But in another mishnah from Nedarim the two tannaim disagree over the meaning of “Until pene’ Pesah.” R. Meir seems to be certain of this statement’s meaning—it means before Pesah begins. But R. Yose seems to think it is doubtful—maybe it means until Pesah is over in which case his vow is effective until Pesah is over.

R. Hanina b. Avdimi solves the problem by reversing the positions in the baraita about the vows. Now R. Meir is the one who holds that a person does enter themselves into doubt. “Untile before” could mean “until it ends.” R. Yose says that a person does not enter themselves into doubt.

Abaye limits the dispute to the case referred to in the mishnah—two groups of daughters from two wives. But if a man has only one wife (poor guy or lucky guy, guess that depends on your perspective) then “elder” and “younger” are taken literally. A middle daughter would not be called “elder” or “younger” but “middle.”

If the middle one is not called “elder” or “younger” then the middle one of the second group could not be called elder. So why shouldn’t she be permitted to marry?