QUESTION: The Mishnah states that a mother-in-law and daughter-in-law may not
testify about the death of the other's husband. Each woman is suspected of
maliciously attempting to harm the other by lying about the other's husband,
due to the enmity they have for each other. The Gemara explains that the
mother-in-law hates the daughter-in-law because the daughter-in-law is
"eating all the fruits of her labor" (because the son gives his wife
everything his mother prepared for him).
The Tana'im argue about the source of the inverse hatred, though. Why does
the daughter-in-law hate the mother-in-law? Rebbi Yehudah, in a Beraisa, says
that she hates her mother-in-law because her mother-in-law reveals all of the
secrets of what her daughter-in-law does in private to the daughter-in-law's
husband. The Rabanan say that she hates her mother-in-law simply because her
mother-in-law hates her, as the verse says, "As water reflects a face back to
a face, so one's heart reflects the other's heart" (Mishlei 27:19). The
Mishnah follows the view of the Rabanan, and their view is the Halachah.
The Gemara then discusses the trustworthiness of a woman to testify about the
husband of her *potential* mother-in-law ("Chamosah ha'Ba'ah l'Achar
mi'Kan"). This refers to a woman who is married, but will fall to Yibum if
her husband dies, and her husband's brother has a different mother than her
husband. The Gemara asks whether such a woman hates her potential mother-in-
law or not.
The Gemara cites proof from the Mishnah later (118a) which discusses a case
where a woman's husband and her father-in-law travelled abroad to Medinas
ha'Yam. The woman testifies that her husband and the husband of her mother-
in-law both died. The Mishnah states that she is not believed to permit her
mother-in-law to remarry. The Gemara asserts from here that a woman does hate
her mother-in-law now, even though it is only due to her anticipated hatred.
RASHI explains that the Gemara's proof is that we see that the daughter-in-
law hates the mother-in-law even when both husbands are in Medinas ha'Yam and
the mother-in-law does not have the opportunity to reveal to her son the
secrets of her daughter-in-law. Even though right now the daughter-in-law has
no reason to be angry at her mother-in-law since her husband is away,
nevertheless she is afraid that when her husband returns her mother-in-law
will reveal her secrets.
Why does Rashi mention only Rebbi Yehudah's reason for why a daughter-in-law
hates her mother-in-law? He should have explained the Gemara's proof
according to the Halachic reason, that of the Rabanan, who say that the
daughter-in-law feels reciprocal hatred for her mother-in-law, simply because
her mother-in-law hates her.
ANSWER: Rashi means that according to the Rabanan, the Gemara has no proof
from the Mishnah later. The reason the mother-in-law hates the daughter-in-
law is because the daughter-in-law eats the fruit of her labors.
Consequently, according to the Rabanan, as long as the daughter-in-law is
benefiting from the work of the mother-in-law, she will also hate the mother-
in-law because of the reciprocal hatred. If so, she will certainly hate the
mother-in-law even when their husbands are away, because the mother-in-law
still hates her at this very moment!
For this reason, Rashi understands that the Gemara's proof from the Mishnah
later is *only* according to the reasoning of Rebbi Yehudah, that the
daughter-in-law hates the mother-in-law because she reveals her secrets.
According to that reason, the Gemara has a good proof that we must be
concerned for anticipated hatred, because while the daughter-in-law's husband
is away (and cannot hear any secrets) she has no reason to hate her mother-
in-law. (The Gemara is assuming that Rebbi Yehudah agrees to the Halachah of
the Mishnah later, that the daughter in law cannot testify about her mother
in law when both husbands are abroad.)
This seems to be the way the RITVA understands Rashi as well. The Ritva adds
that if the Gemara can only prove according to *Rebbi Yehudah* that the
daughter-in-law hates the mother-in-law because of anticipated hatred, how
can we prove that the Rabanan agree to him on this point? The Ritva answers
that there is no reason to assume that the Rabanan should *not* agree with
Rebbi Yehudah on that point. Thus, by proving that Rebbi Yehudah holds that a
woman hates her mother-in-law due to anticipated hatred, we can assume that
that is the opinion of the Rabanan as well.