GEMARA

32a (Abaye): All agree about one witness (that he obligates paying), when he is Pasul (disqualified from swearing).

32b: He means that both parties are Pasul. The obligation to swear reverts to the defendant. Since he cannot swear, he must pay.

41a: One cannot reverse an oath mid'Oraisa (refuse to swear, and require the claimant swear to collect). One can reverse an oath mid'Rabanan.

R. Yosi holds that for Torah oaths, if the defendant is Pasul, we reverse the oath onto the claimant, and the defendant pays. Mid'Rabanan oaths are enactments. We do not enact (to reverse the oath) for an enactment.

45a (Mishnah - R. Yosi): Regarding a Shevu'ah to receive, if both are disqualified, the Shevu'ah returns to its source;

R. Meir says, they divide the disputed money.

47a (R. Ami): Our teachers in Bavel say that R. Yosi means that it returns to Sinai. Our teachers in Eretz Yisrael say that it returns to the defendant.

(Rav Papa): 'Our teachers in Bavel' refers to Rav and Shmuel;

(Mishnah): Similarly, orphans only collect after swearing.

(Rav and Shmuel): They must swear to collect from the orphans of Levi (the borrower), i.e. if their father (Reuven) died before Levi. If Levi died first, Reuven could collect from the orphans only if he swore that he was not paid. One does not inherit money that required an oath to collect it.

'Our teachers in Eretz Yisrael' refers to R. Aba;

One witness testified in front of Rav Ami that Reuven grabbed an ingot from Shimon. Reuven said 'yes, I grabbed it. It is mine!'

Question (Rav Ami): We cannot force Reuven to pay without two witnesses. We cannot exempt him, for there is a witness. He cannot swear that the witness lies. Since he admits that he took it, he is like a thief!

Answer (R. Aba): He must swear, but he cannot, therefore he must pay.

Support (for R. Aba - Rava - R. Ami's Beraisa): "Bein Sheneihem" - the oath is between the two parties, not between their heirs.

Reuven says 'your father owed my father 100'; Shimon knows that his father owed 50, but not whether he owed more.' We need a verse to exempt Shimon only if his father would need to pay in such a case!

48a (Rav Nachman): If the Halachah follows Rav and Shmuel, this is even if Reuven never tried collecting. If the Halachah is not like Rav and Shmuel, they can collect even if Reuven tried collecting in Beis Din.

Question: Is Rav Nachman unsure? Rav Yosef bar Minyomi said that a case occurred in which Rav Nachman ruled that they collect half!

Answer: Rav Nachman meant that if Rav and Shmuel's explanation of R. Meir is correct, we do not distinguish whether Reuven tried collecting. Rav Nachman himself holds that the Halachah follows R. Yosi.

Bava Basra 33b: Yosef challenged David 'you are on my land!' David said 'I bought it from you, and I ate the years of Chazakah!' David brought one witness who said that David ate the years of Chazakah.

Rabanan: This is like R. Aba's law of the ingot!

34a - Rejection (Abaye): No. There the witness comes to obligate Reuven. Here, the witness comes to support David!

(Abaye): If David says that he bought a field and ate the years of Chazakah, and one witness testified that he ate Peros for two years, this is like R. Aba's law. (David cannot swear unlike the witness, so he must pay for the Peros.)

Bava Metzia 97b (Mishnah): If Reuven borrowed Shimon's cow for half the day and rented it for half the day, and it died, if Shimon claims that the borrowed cow died, and Reuven is unsure, he must pay.

Question: This is unlike Rav Nachman, who says that if Levi claims that Yehudah owes him money and Yehudah says 'I don't know', he is exempt!

Answer: Our Mishnah discusses a case like Rav Nachman said (elsewhere), that Reuven must swear to Shimon, like Rava's case;

(Rava): If David claimed 100 from Levi, and he admits to 50, but is unsure about the rest, Levi must swear, but he cannot, so he must pay.

RISHONIM

Rif (29b): Presumably, the Halachah follows R. Aba. Therefore, if both of them were Pesulim, the oath returns to its source, and since he cannot swear, he must pay. We always rule like this, e.g.in Bava Basra 34a, in R. Aba's case, and in Bava Metzia. Only regarding orphans collecting from orphans we hold like Rav and Shmuel. Some say that when both are Pesulim, the Halachah follows R. Yosi, who says that they divide, like Rav Nachman ruled. This is wrong. Rava is Basra, and he rules like R. Aba. No one challenged Rava. Also Abaye is Basra, and he explains that the oath reverts to the defendant.

Rambam (Hilchos To'en 2:4): For a Torah oath, if both of them were Pesulim, the oath reverts to the defendant. Since he cannot swear, he must pay.

Rosh (7:7): When both are Pesulim, the claimant collects without swearing (32b). When only the defendant is Pasul, the claimant must swear in order to collect. This is to protect the defendant, lest every Rasha impose oaths against him and take all his money. Here it seems that Rav Nachman argues with R. Aba. In Bava Metzia, he holds like Rava, who holds like R. Aba! Also, we hold like Rav Nachman in monetary laws; Rav Nachman ruled in practice and divided the money. However, the Halachah follows R. Aba, that if one must swear, but he cannot, he must pay! This is brought throughout Shas. Also, the Gemara says that if one ruled like Rav and Shmuel, it stands, and if one ruled like R. Elazar (that orphans can always collect from orphans), it stands. It did not mention Rav Nachman (that they divide the money)! Also, how did the Gemara know that Rav and Shmuel, who say that orphans cannot collect from orphans (if the borrower died first) argue with R. Aba? This is like R. Aba, that one who cannot swear loses! Rather, if they held like R. Aba, since the lender's heirs have a document, and they should collect, just Chachamim obligated a Shevu'ah to collect from orphans, they should collect without an oath. We say 'the oath returned to the one who needed to swear, and since he cannot, he loses' only when the money depends primarily on the oath, e.g. a Pasul who must swear to be exempt. Here, the money depends primarily on the document. The oath is a mere enactment. We cannot say that the oath returns to the one who must swear, and he loses. Rather, the borrower's heirs cannot refute the document. To exempt themselves, they would need to swear that their father paid. Therefore, if Rav and Shmuel held like R. Aba, they would obligate them to pay. Rav Nachman holds like R. Aba regarding 'I do not know about 50', and orphans collecting from orphans. R. Yosi agrees that since he cannot swear, he must pay, just he fines the claimant for being Pasul (so he collects only half). There is no proof from 32b. Abaye means that a witness who denied knowing testimony is liable for Shevu'as ha'Edus, for his testimony would have forced paying half. The Gemara did not need to specify.

POSKIM

Shulchan Aruch (CM 92:7): For a Torah oath, if both of them were Pesulim, the oath reverts to the defendant. Since he cannot swear, he must pay.

Beis Yosef (DH v'Im): The Rosh rules like Rav Nachman, like Rav Hai Gaon and R. Tam. The Rambam and Ri rule like R. Aba, like the Rif. We follow them.

Rema: Some say that they divide. I say that we should rule like this, for ha'Motzi mi'Chavero Alav ha'Re'ayah.

Darchei Moshe (6): Since Poskim argue, and the Rosh who is Basra says that they divide, one cannot take money without a clear proof.

Shach (9): The Rosh's opinion is primary. Rav Nachman divided in practice. We find that he holds like R. Aba. The Ramban said that he merely explains R. Meir, but it is difficult to say that the Sugyos in Bava Metzia are unlike the Halachah. Tosfos challenged R. Tam; the Ran answered all his questions.

Gra (18): We hold like R. Yosi against R. Meir, and like Rav Nachman, and he ruled in practice. R. Yosi fines because the claimant is also obligated to swear, and he cannot. The Halachah follows Rav and Shmuel, R. Aba, and Rav Nachman. All hold like R. Aba, just R. Aba says so only for Torah oaths (which we do not reverse), for then the claimant need not swear. Rav and Shmuel say so even for mid'Rabanan oaths, e.g. orphans. We said that we should not add to this. I.e., for Torah oaths we hold like R. Aba. When both cannot swear, we follow R. Yosi. However, why was Rava unsure if the Halachah follows R. Aba, and why was Rav Nachman unsure if the Halachah follows Rav and Shmuel They do not argue!