1) WINNING THE CASE WITH A FORGED "SHTAR"
QUESTION: The Gemara records a case in which a defendant presented a Shtar to support his claim that he bought the field from the original owner. When the original owner claimed that the defendant's Shtar was forged, the defendant whispered to Rabah that his Shtar indeed was forged, but that he did have an authentic Shtar but it was lost. Rabah ruled that the defendant is believed with a Migu (since he could have maintained his original claim and not admitted that the Shtar was forged). Rav Yosef argued and said that a Migu is ineffective in this case, because the Shtar is worthless based on the admission of the bearer of the Shtar himself.
The RASHBAM explains that according to Rav Yosef, the Migu in this case is like a "Migu b'Makom Edim," a Migu that counters the testimony of witnesses, because the defendant himself admitted that the Shtar is forged, and "Hoda'as Ba'al Din k'Me'ah Edim Dami" -- the admission of the defendant is tantamount to testimony of a hundred witnesses.
What does the Rashbam mean? Why should this Migu be considered a Migu that counters witnesses? The defendant is not contradicting his claim that the Shtar is forged and now saying that it is not forged. Rather, he is saying that although it is forged, he has another reason why his claim that the field is his should be believed -- because he had another, genuine Shtar which he lost. Why, then, should he not be believed with a Migu, and how is his second claim contradicted by Hoda'as Ba'al Din? This Migu is the same as every other Migu; the defendant, by his own admission, says that one claim (the claim of the Migu) is not what he is claiming, and that he instead is making a different claim! This is the way every Migu works. Why should the defendant who is holding the Shtar not be believed in this case? (ROSH 3:12)
(a) Perhaps the Rashbam means that the Migu of the defendant is not similar to an ordinary Migu. Normally, the claim of the Migu which a defendant could have said is that his opponent does not have sufficient proof to support his claim. Since his opponent does not have a strong argument, the defendant is able to present another argument to defend his position in which he admits that the claimant does have a good claim, but that the object nevertheless still belongs to him, the defendant. In this case, however, the claim of the Migu which the defendant could have said is that the claimant indeed has a valid claim -- because he was the previous owner of the land and the defendant does not have a Chazakah -- but nevertheless he (the defendant) is entitled to the land because he has a new proof of ownership (the Shtar) to contradict the claim of the original owner. Perhaps a Migu can be used only against a claim which is inherently weak; one cannot override a valid claim with a Migu (that he could have brought a proof to contradict the opponent's claim).
(The KOVETZ SHI'URIM (2:3:12) suggests a similar approach. However, he writes that the Rashbam can be understood only if a Migu gives the person's claim the credibility of the alternative claim (which he did not say, but which he could have said), and not if a Migu is merely based on the logic that if the person wanted to lie, he would have said a more effective lie. According to the above approach, the Rashbam's comments can be understood even if the mechanism of Migu is based on this logic.)
(b) Alternatively, the Rashbam may have understood the Gemara as TOSFOS (end of DH Amai) does. Tosfos writes that Rav Yosef did not accept the defendant's new claim that his Shtar is forged and that he lost the original Shtar, because he maintains that a person cannot change a claim presented in court (see Insights to 31:2). This indeed seems to be the opinion of the Rashbam (33b, DH Meheman).
Accordingly, when the Rashbam (32b, DH Amai) writes that this is not comparable to an ordinary Migu because in the case of an ordinary Migu both claims can be true -- the one that the person could have claimed and the one that he actual claims -- he does not mean that the claim that the person could have claimed is not true in this case, but rather he means that the claim that he is claiming (i.e. that he had another Shtar which he lost) is not true, since it is contradicted by his previous admission that this Shtar is the original Shtar. This seems to be the way the HAGAHOS MAIMONIYOS (Hilchos Malveh v'Loveh 14:40) understands the Rashbam. The ROSH, who argues with the Rashbam, follows the view of the RAMAH and others who maintain that a person is permitted to change his defense in court as long as his original defense is not contradicted by witnesses.
2) VALIDATING AN INVALID "SHTAR"
QUESTION: The Gemara records a case in which a defendant presented a Shtar to support his claim that he bought the field from the original owner. When the original owner claimed that the defendant's Shtar was forged, the defendant whispered to Rabah that his Shtar indeed was forged, but that he did have an authentic Shtar but it was lost. Rabah accepted the defendant's second claim, based on a Migu that he could have remained quiet and won the case with his original claim (that the Shtar he was holding was a valid Shtar).
Why would he have won the case? When a litigant claims that his opponent's Shtar is forged, the bearer of the Shtar must be Mekayem (validate) the Shtar. This Shtar obviously was not validated earlier, because if it had been the claimant would not have been able to claim that it was forged.
(a) The ROSH writes that Rabah did not give unconditional credibility to the defendant. Rather, he ruled that if the Shtar is so well forged that the defendant succeeds in bringing witnesses to validate the Shtar, then he will be believed with a Migu.
If witnesses would validate the Shtar, why would Rabah believe the defendant to say that this is not the original Shtar and that he had another Shtar? Making such a claim would contradict the witnesses whose signatures on the Shtar have been validated and who claim that this Shtar is the genuine, valid Shtar that was written for the sale. Consequently, the defendant's Migu would contradict the testimony of witnesses and should not be believed!
It is true that Rabah himself suggests that a Migu is believed against the testimony of witnesses (31a). However, the Rashbam there writes that Rabah changed his mind. In addition, Rav Yosef in the Gemara here does not argue with Rabah based on the rule that a Migu is not believed against witnesses, but rather he presents a different argument against Rabah's ruling.
Perhaps the Rosh maintains that even though witnesses testify that the Shtar is an original bill of sale, nevertheless the defendant's claim that he had another Shtar which was lost does not contradict the witnesses because it is possible that the seller wrote two Shtaros for the same sale.
(This approach might be an additional reason for why the Rosh does not accept the Rashbam's explanation that the defendant was presenting a second claim in court ("To'en v'Chozer v'To'en"; see previous Insight). The Rosh maintains that the second claim is not considered a separate, different claim, because it is not contradicted by the first claim. The first claim (that this is the genuine Shtar) does not preclude the second claim (that there is another Shtar that was lost, which was the genuine Shtar), because it is possible that the seller wrote two Shtaros for this sale.)
(b) The RASHBAM cites RABEINU CHANANEL who explains that the Shtar was not a complete forgery. Rather, it was a "Shtar Amanah," a "Shtar of trust" written before any transaction was made. Since the Shtar is actually signed with the witnesses' handwriting, it is clear that the defendant would have been able to be Mekayem the Shtar.
The Rashbam adds that it is possible that the Shtar is a complete forgery, but the defendant claims that it is such a good forgery that the witnesses themselves would be fooled by it (and think that the forged signatures in the Shtar are indeed their signatures) and be Mekayem it. (It seems that the witnesses were brought to validate the Shtar, and they were about to validate it when the defendant whispered his admission to Rabah.) Therefore, had he wanted, he would have been able to be Mekayem the Shtar.
(c) The RAMBAN and RASHBA write that this question is the basis for Rav Yosef's reason for rejecting the claim of the defendant. The Shtar was not Mekuyam, and therefore the defendant had no Migu. Rabah maintained that the Shtar could be validated even after the defendant admitted that it was false (as the Rosh maintains). Rav Yosef argues that once the defendant admits that the Shtar is false, validating in court will be a farce. Since the court does not allow the defendant to validate the Shtar, he does not have a Migu and Beis Din believes the claimant who says that the sale never took place.
3) AN "AREV" WHO DEMANDS PAYMENT FROM THE BORROWER
QUESTION: The Gemara relates an incident in which an Arev, a guarantor, came to collect 100 Zuz from the borrower whose loan he guaranteed and which he paid to the lender on behalf of the borrower. He presented a Shtar to the borrower to prove that he paid the loan. The borrower rejoined that he had already repaid the Arev. The Arev then claimed that it is true that the borrower repaid him, but that he gave the money back to the borrower as a loan, and it is that money which the Arev now demands from the borrower.
Abaye ruled that the Arev is not believed with a Migu that he could have claimed that the money was never repaid to him, since he admits that it was repaid and that the Shtar he is holding is not a valid Shtar for the debt that he claims is owed to him.
The RASHBAM (DH d'Parati) explains that the Arev was an "Arev Kablan" (a guarantor who commits himself to pay back the debt even when the borrower has money with which he can repay), or that the lender stipulated at the time of the loan that he has the right to collect the money from the Arev first if he wants without first claiming it from the borrower.
How does the Rashbam know that this incident involved an Arev Kablan? Perhaps he was a normal Arev who paid the debt because the borrower had no money with which to pay; the borrower later obtained some money, and the Arev went to collect from him! (SHITAH LO NODA L'MI cited by the Shitah Mekubetzes; see his answer there.)
Moreover, why does the Gemara need to point out that the case involved an Arev who was collecting from the borrower? The Gemara could have related the same Halachah in a case where the lender himself (and not an Arev) comes to collect money from the borrower. The borrower claims that he repaid, and the lender agrees to the borrower's claim but asserts that he loaned the money a second time to the borrower.
ANSWER: The Gemara says that the Arev presented the Shtar to the borrower. The implication of the Gemara is that he presented to the borrower the original Shtar that the borrower had written for the lender. That is, when the Arev paid the lender, he took the Shtar from the lender in order to use it to collect the money from the borrower, as the Rashbam (DH v'Ha Shtara) explains (in contrast to the explanation of the RASHBA). A normal Arev does not take the place of the borrower, but rather he guarantees the loan and pays it back for the borrower in the event that the borrower cannot pay. Therefore, the lender would not give his Shtar to the Arev, since the Arev is a third party and is not the one who borrowed the money (see Bava Metzia 77b). Instead, the lender writes to the Arev a new Shtar saying, "I received money from the Arev as repayment for the borrower's loan." Since, in the case of the Gemara, the lender gave the original Shtar to the Arev, it must be that he is an Arev Kablan who himself is considered a borrower (as the Gemara in Bava Metzia there says). Upon payment, he receives the original Shtar from the lender, and he now becomes a lender and collects the money from the borrower. That is why the Rashbam explains that the Arev in this case is an Arev Kablan.
The reason why the Gemara specifically chooses this case is as follows. Had the case involved a normal lender it would have been obvious to Rav Idi bar Avin that Abaye is correct, and that this case is comparable to a case in which the lender admits that the Shtar is forged. Even if the lender gave a new loan to the borrower, the old Shtar is invalid because the loan of that Shtar was repaid, and this is a new loan. If this would have been the original loan, then there would have been no point in having the lender take the money only to give it back to the borrower. However, in the case of an Arev Kablan, it is possible that the Arev asked for the money because he thought that the borrower had money with which to pay back. Conversely, the borrower paid the Arev Kablan because the Arev Kablan never loaned money to him, and therefore he did not know that the Arev Kablan would agree to let him pay back later. In such a case, when the Arev Kablan returns the money to the borrower as a loan, it is possible that it is not a new loan, but rather he is allowing the borrower to hold on to the money until later. Hence, the Shtar of the original loan is still a valid Shtar. That is why Rav Idi bar Avin thought that specifically in the case of an Arev, the Arev might be believed with a Migu. (M. KORNFELD)