Rav Nachman argues and says that Beis Din does institute its own Heter for
her; the Rabanan are the ones who grant permission to the woman to remarry,
and even if the husband returns, it does not make the ruling an error.
Rather, if the husband returns, then their permission for her to remarry is
revoked.
Rava attempts to prove that Ze'iri is correct and that when the husband
returns, Beis Din is considered to have made a mistake. Rava says that in a
case where Beis Din issued a ruling about a certain questionable food item
and permitted it, and then they readdressed the question and prohibited the
food because they saw a reason to do so, and then they permitted it again --
no one would listen to that Beis Din to eat the questionable item. Here,
though, the same thing is happening, and yet the Beis Din's words are
accepted: Beis Din permits the woman to remarry based on the testimony of a
single witness, and when two witnesses come and testify that the husband is
alive, the Beis Din prohibits her to remarry, and when another single
witness comes and says that her husband is dead, the Beis Din again permits
her to remarry! Why does Beis Din revert to its initial Heter? If Beis Din
instituted the Heter that she may remarry based on the testimony of one
witness, then why do they allow her to remarry the second time? It must be
that there is no enactment of Beis Din involved, but rather that they just
made a mistake in applying the Torah's Heter.
What is Rava's proof for Ze'iri? In the case where a second single witness
comes after a set of two witnesses, it should become a case of "Trei
u'Trei" -- two against two -- in which case the woman is not permitted to
get married to anyone other than one of the two witnesses who say that her
husband is dead (as we learned on 88b). But this has nothing to do with
whether the Heter is a specific enactment of the Rabanan, or whether the
Rabanan permitted her to remarry based on a mistake! In either case, the
laws of "Trei u'Trei" should apply here!
(a) RASHI (DH Ki Hadar, as explained at length by the Rishonim), says that
the second single witness did *not* corroborate and uphold the testimony of
the first single witness, and thus it is not a case of "Trei u'Trei."
Rather, the second single witness said an entirely new testimony. He said
that *now* the husband is dead, even though he was not dead at the time that
the first witness testified that he was. The second witness is giving a new
reason to permit her to remarry.
Accordingly, Rava's proof seems to be as follows: If we permit her to get
married as a specific Heter instituted by Beis Din, then really there is no
strong proof that her husband is dead, but nevertheless the Rabanan permit
her to remarry (Mishum Iguna), since we do not know where the husband is and
a single witness says that he is dead. If the Heter is a specific enactment
of the Rabanan, then when two witnesses testify that the husband is still
alive, thereby requiring the woman to leave her second husband and to suffer
all of the penalties of the Mishnah (87b), then she certainly will not want
to get married again based on the testimony of another single witness with
the same weak Heter of the Beis Din. Hence, there is no point in issuing the
Heter for her a second time. (This is the meaning of "Lo Mashgechinan
Lehu" -- the woman will not listen to the Heter of Beis Din since she has
suffered from the Heter once before.)
In contrast, if the reason we permit her to remarry is not because of a
provision of Beis Din but because Beis Din feels that there is sufficient
*proof* that her husband died, then even though it turns out that the first
time Beis Din was mistaken and the single witness turned out to be a liar
and the woman did not check out the facts before she remarried, nevertheless
when another single witness comes we have no reason to assume that *he* is a
liar or that the woman will not check out the facts this time. (Just because
they were mistaken in one case, Beis Din does not lose their credence for
all future matters.) Therefore, Beis Din may permit her to remarry the
second time a single witness testifies.
(In Insights to 88a, we discussed why a single witness is trusted here to
permit a woman to remarry. Tosfos says that it is an enactment of the
Rabanan and is not based on a law in the Torah. Other Rishonim maintain that
the Torah permits the Rabanan to rely on circumstantial evidence in such a
case. The Gemara here seems to be debating this very point. Ze'iri says that
it is not a Heter of the Rabanan, but that the Rabanan are relying on a
Halachah in the Torah. In contrast, Rav Nachman says that it is a Heter of
the Rabanan -- that even though there is not sufficient proof to permit her
to remarry mid'Oraisa, the Rabanan nevertheless allowed her to remarry.)
(b) The RASHBA cites RAV MOSHE BAR YOSEF who explains that Rava's proof is
as follows: If the Beis Din would be permitting her to remarry based on
their own Heter, then once they have contradictory evidence about the
permissibility of a food or about a woman's marital status, they should rely
on the Chazakah that the food, or the woman, is Asur. That is, since until
now the food was Asur to eat and the woman Asur to remarry, they remain
Asur. Nevertheless, after the second single witness comes and supports the
testimony of the first single witness, we consider it "Trei u'Trei" and we
permit her to marry one of the witnesses.
Why may she marry if there is a Chezkas Isur? It must be that when Beis Din
permits her to get married based on the testimony of one witness, it is not
a Heter, but rather the testimony of one witness is a proof that the husband
is dead. If two witnesses come later and testify to the contrary, then we
declare the testimony -- and the ruling based on that testimony -- of the
first witness to have been a mistake.
The logic of Rav Moshe bar Yosef may be understood as follows. If it is a
Heter of the *Rabanan* that is permitting her to remarry, then what the
Rabanan enacted was that the first witness who comes is given the
trustworthiness of two witnesses to permit the woman to remarry. If so, why
do we not believe that witness when two witnesses come and contradict him?
Is it because in a case of "Trei u'Trei," we do *not* allow her to marry one
of the witnesses? But when a second single witness comes, we *do* allow her
to marry one of her witnesses, and if so apparently by "Trei u'Trei" there
is no basis to allow her to marry one of the witnesses. (This is what the
Gemara's means by bringing an example from forbidden foods. If the Rabanan
prohibit a certain food which they once permitted, how can they suddenly
decide to embrace their original ruling, and permit the food, when *no
further proof* has come to that effect!)
It must be that the first witness was never given the trustworthiness of two
witnesses. Rather, the *Rabanan permitted her* to remarry based on only the
testimony, and trustworthiness, of a single witness, considering it to be
sufficient proof. Consequently, when two witnesses come, they override his
testimony, and when another single witness comes and corroborates his
testimony, he joins with the first witness to increase his degree of
trustworthiness, so that their testimony together now counters the other set
of two witnesses.
In short, if it were a Heter enacted by Beis Din that allows her to remarry,
then the Rabanan made a new way of looking at things: we view one witness
like two witnesses. If the Rabanan are merely applying the Torah's Heter and
not making their own enactment, then the Torah is permitting us to accept
the testimony of a single witness, even though we might end up having made a
mistake. (M. Kornfeld)