Question: If so, we should similarly learn from "(David tore his clothing) for Sha'ul and for Yonasan" that one must know for whom he tears. This is not true!
(Beraisa #1): If they told a man that his father died, and he tore his clothing, and later he learned that really, it was his son who died, he was Yotzei (he fulfilled the Mitzvah to tear).
Answer: In the Beraisa, the man was told only that a relative died. He thought it was his father, but he did not say that he is tearing for his father;
In our Mishnah, he specified whose vow he annuls.
Support (Beraisa #2): If they told a man that his father died, and he tore his clothing, and later he learned that it was his son who died, he was not Yotzei;
If they told him that a relative died, and he thought that it was his father, and he tore, and later he learned that it was his son who died, he was Yotzei.
(The Reisha contradicts Beraisa #1. To resolve this, we must answer like above (b), that the case of Beraisa #1 is really like the Seifa of Beraisa #2.)
Rejection (Rav Ashi): If he learned of his mistake Toch Kedei Dibur (within the time needed to say three or four words), he was Yotzei. If he learned after this, he was not Yotzei.
In Beraisa #2, he found out after Toch Kedei Dibur. In Beraisa #1, he found out within Toch Kedei Dibur. (Ran - Rav Ashi agrees that one was Yotzei if he intended for the wrong Mes, without specifying. He merely gives a better resolution of the Beraisos.)
Support (Beraisa): A sick person (Levi) fainted. It appeared as though he died. His relative (Yakov) tore. Later, Levi really died. Yakov was not Yotzei.
(R. Shimon ben Pazi): If Levi died Toch Kedei Dibur of the tearing, Yakov was Yotzei.
The Halachah is, one may retract or correct anything within Toch Kedei Dibur, with four exceptions: blasphemy, idolatry, Kidushin, and divorce.
A VOW ABOUT TWO SPECIES
(Mishnah): If a woman vowed 'figs and grapes are forbidden to me', if her husband affirmed the vow regarding figs, the entire vow is affirmed;
If he annulled the vow regarding figs, it is not annulled (at all. Some say, it is not annulled regarding grapes.) He must annul the entire vow.
If she said 'figs are forbidden to me, and grapes are forbidden to me', these are two vows.
(Gemara): Our Mishnah is like R. Yishmael:
(Beraisa - R. Yishmael): If she said 'figs and grapes are forbidden to me', and he affirmed regarding figs, the entire vow is affirmed - "Ishah Yekimenu v'Ishah Yeferenu." (We read this like Yakim Mimenu, he will affirm from (i.e. part of) it.)
If he annulled the vow regarding figs, it is not annulled. He must annul the entire vow;
R. Akiva says, "Ishah Yekimenu v'Ishah Yeferenu" - just like partial affirmation suffices, also partial annulment suffices.
R. Yishmael: It does not say "He will annul Mimenu"!
R. Akiva equates annulment to affirmation. Just like affirming part of a vow affirms the whole vow, also regarding annulment.
(R. Chiya bar Aba): Chachamim disagree with R. Yishmael and R. Akiva, and equate affirmation to annulment;
Just like partial annulment annuls only (that) part of the vow (Ramban's text - does not work at all), also partial affirmation.
(Mishnah): If she said 'figs are forbidden to me (and grapes are forbidden to me', these are two vows).
(Rava): Our Mishnah is like R. Shimon, who says that an oath 'to you and to you...' is considered one oath, unless he says 'Shevu'ah' to each person.
ONE WHO THOUGHT HE CANNOT ANNUL
(Mishnah): If a man knew about vows, but did not know about annulment, he can annul when he finds out;
If he knew about annulment, but did not know that what his wife said is a vow:
Version #1: R. Meir says, he cannot annul (at all. There is no 'Yom Shom'o' when he first heard and knew that it is a vow);
Chachamim say, he can annul (that very day).
Version #2: R. Meir says, he cannot annul (after the day he heard. It is called 'Yom Shom'o', even though he does not know that it is a vow. He can annul that very day);
Chachamim say, he can annul (the day he finds out that it was a vow). (end of Version #2)
(Gemara - Beraisa - R. Yehudah) Contradiction: "Without seeing" excludes a Suma (blind person. He is not exiled to a refuge city if he unintentionally kills someone);
R. Meir says, this includes a Suma. (Tosfos, Rosh - in the Beraisa, R. Meir follows reasoning (to obligate exile, for he was Shogeg), even if it is unlike the connotation of the verse (that he sees, just he did not see the victim). In the Reisha of the Mishnah, R. Meir agrees that he can annul later, i.e. because his silence was not in order to affirm.. This is like the connotation of the verse, unlike reasoning! Ran - according to Version #1, in the Beraisa, R. Meir obligates one (a Suma) with partial knowledge of what happens around him like one with full knowledge, but in the Mishnah he does not consider partial knowledge (of the vow) to be like full knowledge. Chachamim hold just the opposite in both cases! According to Version #2, only R. Meir contradicts himself. In the Reisha of our Mishnah, he agrees that he can annul when he finds out. I.e., partial knowledge (of annulment) is not like full knowledge. In the Beraisa he holds differently!)