The Gemara explains the difference between this case and the cases in the
other Mishnayos (12b, 13a) in which Rebbi Yehoshua says that a Migu *cannot*
be used to support a person's claim in court (12b and 13a). The Gemara says
that the difference between the cases is that in the case in the Mishnah
here, "there is no slaughtered ox in front of you," while in the cases where
Rebbi Yehoshua does not hold that Migu works, "there is a slaughtered ox in
front of you." What is the meaning of the allegory of a slaughtered ox, and
how does it reflect a logical distinction between the different cases?
(a) TOSFOS (DH Hasam; 15b, DH u'Modeh; 18a, DH Iy) and other Rishonim give
the most straightforward approach. Tosfos points out that there are two
cases in which we see Rebbi Yehoshua does not apply a Migu. One case (in the
Mishnah on 12b) is where the husband finds his newly married wife to be a
Be'ulah, and the woman claims that she was not a Be'ulah at the time of the
Erusin, but that she was raped after the Erusin. The woman is not believed
even though she could have said that she was a Mukas Etz (which would have
been a better claim than saying that she was raped, because with the claim
of "Mukas Etz" she would have been permitted to marry a Kohen). The second
case is that of "Nistarah" (in the Mishnah on 13a), in which a woman
secluded herself with an unidentified man, and, when questioned, she said
that although she had relations with the person, he was Kasher and was not
the type of person who would make her Pesulah to Kohanim. Rebbi Yehoshua
says that she is not believed and we assume that she is Pesulah to Kohanim,
even though she has a Migu that she could have made a better claim and said
that she did not have relations at all with the man (had she made that
claim, she would have benefited by retaining her status of a Besulah and
getting 200 Zuz in her Kesuvah).
In both of those cases, even if she had claimed the better claim (which
would have benefitted her in some way more than her present claim), she
would *not* have prevailed in court; the Migu would not have supported her
claim in court! In the case where the woman claims, "I was raped after the
Erusin," if she would have said that she was a Mukas Etz, she would still
have not been believed according to Rebbi Yehoshua, because the only thing
supporting her claim is that her claim is "Bari" and her husband's claim is
"Shema" (and, also, that she has a Chezkas ha'Guf to say that it happened
after the Erusin). Rebbi Yehoshua, though, holds that "Bari v'Shema" is not
a reason to win in court (12b; Tosfos 13a, DH Rav Asi)!
Similarly, in the case of Nistarah, had the woman said that she did not have
relations with the man, she would not be believed, because Rebbi Yehoshua
holds, "Ein Apotropos l'Arayos" -- we assume that she had relations because
there is no one watching to make sure that Z'nus does not occur (13b; RAMBAN
here).
Rebbi Yehoshua holds that in these two cases, since the Migu is not a true
Migu (since the woman would not have actually been believed with the claim
of the Migu), we must suspect that the woman might be intentionally lying in
order to win her case. She knows that had she said the better claim she
would have lost the case, and therefore she says the weaker claim in order
to win the case. This is unlike any Migu anywhere else in Shas (Ramban). In
every other Migu, there is nothing that the person gains with the weaker
claim that he would not have gained with the stronger claim. It is only this
type of Migu that Rebbi Yehoshua does not accept. This type of Migu is
referred to as, "Shor Shachut Lifanecha," a "slaughtered ox in front of
you," meaning that there was an act that was done that cannot be denied (and
thus no claim will help the woman win in court).
In the case where the woman claims, "I was raped after the Erusin," the fact
that she is a Be'ulah cannot be denied (it is like a slaughtered ox that
cannot be revived). She has no way of winning her case by claiming that she
is a Besulah; no claim she makes could win her case. Since it is known that
she is a Be'ulah, there is no other claim that could win the case for her,
and therefore it is not a real Migu.
Similarly, in the case of Nistarah, no claim that she could make could undo
the fact that she secluded herself. Her seclusion is an undeniable fact.
Therefore, she has no real Migu to deny that fact and to help her be
believed in court.
In contrast, in the case of our Mishnah where the present owner of a field
says to the son of the original owner, "This field belonged to your father,
and I purchased it from him," the present owner could have denied that the
field ever belonged to the other person's father. By denying it, he would
certainly have won the case and been permitted to keep the field. Therefore,
he has a full-fledged Migu when he says that he bought it. This is what is
meant by "Ein Shor Shachut Lifanecha," -- "there is no slaughtered ox in
front of you" -- that is, there is no obvious fact here that cannot be
denied.
(b) RASHI takes another approach to the Sugya (RASHI 16a, DH she'ha'Peh
she'Asar and DH Hacha; 17b, DH v'Lisni;, 18a DH v'Nisni and DH Aliba d'Man).
He explains that Rebbi Yehoshua only accepts a certain type of Migu -- a
"Migu d'Iy Ba'i Shasik." Such a Migu exists when there is no claim being
made against the person, but it is the person himself who initiates the
claim against himself, while at the same time he dismisses it. In the case
of our Mishnah, nobody challenged the owner of the field, saying that it
belongs to someone else. Rather, the owner himself informed the son of the
previous owner that the field once belonged to his father and that he bought
it from his father.
This is what the Gemara means when it says that in this case, "there is no
slaughtered ox" -- there is claimant, there is nothing in front of us to
provoke a response from the person who has the Migu. (Tosfos learns that the
"slaughtered ox" represents a claim with a proof, and "no slaughtered ox"
refers to a claim without a proof, while Rashi learns that the "slaughtered
ox" represents a claim without a proof, and "no slaughtered ox" refers to
when there is no claim at all.)
According to Rashi, it appears that whenever a claim is presented in court,
Rebbi Yehoshua holds that a Migu can *never* cause a claim to win.
There are difficulties, though, with Rashi's explanation.
1. Tosfos disproves Rashi's explanation from our Mishnah that says "if there
are witnesses that the field once belonged to the father," then the present
owner cannot claim, without proof, that he bought it from the father. If,
like Rashi says, Rebbi Yehoshua holds that a claim alone suffices to refute
the Migu, then why does the Mishnah have to say that if the son of the
original owner of the field *brings witnesses* he is believed? He would be
believed even without witnesses, as long as he comes with an independent
claim!
Rashi might answer that this part of the Mishnah is not just expressing
solely the view of Rebbi Yehoshua. Rather, it is expressing a Halachah with
which everyone agrees, even Raban Gamliel. Raban Gamliel, though, agrees
that the original owner of the land is believed *only* when he has witnesses
and not merely a claim that the land belongs to him. (See also SHITAH
MEKUBETZES, 15b, DH v'Li Divrei Rashi.)
2. The PNEI YEHOSHUA brings another proof for the explanation of Tosfos from
the Gemara earlier. The Gemara (13a) says that according to Rav Asi, Rebbi
Yehoshua holds that the woman *is* believed in a case of Nistarah, when she
secluded herself with a man and she claims that he is Kasher, because she
has a Migu that she could have said that she did not have relations at all.
(According to Rav Asi, Rebbi Yehoshua does not hold of "Ein Apotropos
l'Arayos," and that is why she would be believed had she claimed that she
did not have relations.) According to Rav Asi, at least, it is clear that
Rebbi Yehoshua *does* hold that a Migu works to support one's claim, even
though there is a claim against her (there is a "slaughtered ox" in that
case -- there is something there that is provoking her response, and that is
the fact that she secluded herself with a man). It must be, like Tosfos
says, that Rebbi Yehoshua *does* accept a Migu whenever it is a true Migu
and is not merely a better claim.
To uphold Rashi's explanation, the Pnei Yehoshua answers that perhaps Rashi
would concede that according to Rav Asi, Rebbi Yehoshua accepts a Migu.
Another answer for Rashi might be that even Rashi agrees that Rebbi Yehoshua
accepts a Migu for a woman who has a "Chezkas Heter" to permit her to marry
a Kohen. Since she is not taking anything away from anyone and she is not
making a claim that counters the Chazakah, she is believed. However, to take
away money from another person, which involves overriding a Chazakah (i.e.
that the other person is presently in possession of the money), a Migu will
not work.
In summary, according to Rashi it seems that RebbiYehoshua does not accept
any of the MIgus which we commonly find throughout the Shas. (The RAMBAN
refuses to accept such an approach; he suggests what he himself calls a very
forced answer to explain that even according to Rashi, Rebbi Yehoshua will
accept a normal, and only here he does not accept the Migu in this case.)
Why does Rashi not accept the straightforward explanation of Tosfos? Rashi
gives this explanation because of his reading of the Sugya later (18a; see
Rashi there). Rashi infers from the Gemara later that Rebbi Yehoshua does
not hold that any normal Migu works. However, the question remains, how did
the Gemara there know that this is Rebbi Yehoshua's opinion?
Apparently, the Gemara understood that this is the simplest understanding of
the wording of Rebbi Yehoshua. In the Mishnah, Rebbi Yehoshua presents the
case as, "One who says this field belonged to your father...," where the
present owner initiates the question (and gives us the answer) about the
possession of the field. The Mishnah clearly implies the Migu is accepted
only when the person who has the Migu is the one who informs us that the
field once belonged to the other's father. The simple reading of the Mishnah
seems to support Rashi's explanation.
(c) The BA'AL HA'ME'OR has the opposite Girsa in the Gemara -- in the case
of our Mishnah, there is a "slaughtered ox" in front of him, and that is why
he is believed. The Ba'al ha'Me'or explains that the "slaughtered ox" simply
means that the "Chezkas Mamon" that one person used to have on the property
has come to an end, and now the property is in the hands of someone else --
the person who says that he bought it. Just like in the case of a
slaughtered ox, we say that once a proper Shechitah has been performed, it
no longer has a "Chezkas Isur" (either that it was "Ever Min ha'Chai," or
that it was lacking Shechitah). But the case where the woman claims, "I was
raped after the Erusin," is compared to where the ox is not slaughtered, and
just like the ox is still in its original state of a "Chezkas Isur" (until
we can prove that it was slaughtered properly), the husband, too, still has
a Chazakah on the money of the Kesuvah.