1) THE DIFFERENCE BETWEEN A SHEVU'AH D'ORAISA AND A SHEVU'AH D'RABANAN
QUESTION: The Mishnah (38b) teaches that when one person claims that another person owes him a Maneh, and the defendant denies owing anything, he is exempt from paying as well as from making a Shevu'ah. Rav Nachman (40b) rules that he nevertheless must make a Shevu'ah d'Rabanan, called a Shevu'as Heses, even though he denies everything. The basis for the need for such a Shevu'ah is the assumption that a person would not claim money unless it was actually owed to him.
The Gemara (beginning of 41a) asks, what is the difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan? RASHI (DH Shevu'ah) explains that a Shevu'ah d'Oraisa refers to a Shevu'as Modeh b'Miktzas, which a person must make when he admits to part of a claim. A Shevu'ah d'Rabanan refers to a Shevu'as Heses.
The Gemara explains that one difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan is that a Shevu'ah d'Rabanan may be "exchanged" from the defendant to the claimant, while a Shevu'ah d'Oraisa cannot be "exchanged." Rashi (DH Meipach) explains that in the case of a Shevu'ah d'Rabanan, the defendant may tell the claimant that if he makes a Shevu'ah he may collect the money he claims.
The Gemara says that according to Mar bar Rav Ashi, who maintains that even a Shevu'ah d'Oraisa may be "exchanged," there is another difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan: collecting from the defendant's land if he refuses to make a Shevu'ah. In the case of a Shevu'ah d'Oraisa, if the defendant refuses to make a Shevu'ah but also insists that he owes nothing, Beis Din may order that the debt be collected from his land. In the case of a Shevu'ah d'Rabanan, Beis Din may not collect the debt from the defendant's land (under normal circumstances).
What, though, is the difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan according to Rebbi Yosi, who maintains that Beis Din may seize the defendant's land when he refuses to make even a Shevu'ah d'Rabanan? The Gemara explains that according to Rebbi Yosi, the difference is where the defendant is not trusted to make a truthful Shevu'ah (for example, he lends money with interest; see Mishnah, 45a). If a person who is required to make a Shevu'ah d'Oraisa is suspected of swearing falsely, the opportunity to swear is given instead to the claimant to make the Shevu'ah and take the money he claims. This is not an option in the case of a Shevu'ah d'Rabanan.
TOSFOS (DH Mai) cites RASHI in Kesuvos (88a, DH li'Yedei) who writes that the difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan is that when one makes a Shevu'ah d'Oraisa he must hold a Sefer Torah in his hands while he swears. This is not necessary in when one makes a Shevu'ah d'Rabanan.
Tosfos questions Rashi's explanation. If this indeed is a difference between a Shevu'ah d'Oraisa and a Shevu'ah d'Rabanan, then why does the Gemara here not mention it?
ANSWER: The HAGAHOS MAIMONIYOS (Hilchos Shevu'os 11:5) cites the MAHARAM MI'ROTENBURG who explains that Rashi agrees that a Sefer Torah must be held even when one makes a Shevu'ah d'Rabanan. However, the Gemara in Kesuvos (88a) is discussing a case in which one witness testifies that a woman's Kesuvah has been paid. The Mishnah in Kesuvos (87a) states that in such a case she cannot collect her Kesuvah unless she makes a Shevu'ah that she has not yet been paid. Rava there (87b) gives two reasons for why this Shevu'ah is only mid'Rabanan. The first reason is that all Shevu'os mandated by the Torah exempt a person from payment, while this one enables the woman to collect money. The second reason is that by denying his ex-wife's claim to the Kesuvah money, her former husband denies that his land is a target for collection for the Kesuvah. Accordingly, her Shevu'ah is a Shevu'ah to collect from land, and the law is that mid'Oraisa no Shevu'ah is made on land. For these reasons, Rava concludes that this Shevu'ah is only mid'Rabanan. The only reason why she swears is to appease her former husband; according to the letter of the law, she should not be required to make a Shevu'ah at all.
Since, the reason for making the Shevu'ah in that case is weak, Rashi there explains that she does not need to hold a Sefer Torah when she makes that Shevu'ah. (D.Bloom)
2) DEMANDING TO BE PAID BACK IN FRONT OF WITNESSES AFTER THE LOAN HAS BEEN GIVEN
OPINIONS: The Mishnah (38b) discusses a case in which the claimant says, "You owe me a Maneh," which the borrower openly admits. The claimant continues, "Return it to me only in front of witnesses." If, on the following day, he demands the money from the borrower and the borrower replies, "I returned it already," the borrower is obligated to pay, since he committed to return the money in front of witnesses.
It is apparent from the Mishnah that even though the claim and admission occurs after the loan was given, the demand that the loan be paid back in front of witnesses remains valid. What is the logic behind this? How does the lender have the right to place new conditions on the loan after he has already lent the money?
(a) The MAGID MISHNEH (Hilchos Malveh v'Loveh 15:1) understands that the RAMBAM maintains that this is based on the verse, "Eved Loveh l'Ish Malveh" -- "a borrower is a slave to the one who lends to him" (Mishlei 22:7). When a person takes a loan, he accepts upon himself certain obligations towards the lender, including complying with any conditions he may set for the repayment of the loan even after the loan was made.
The RITVA (40b) quotes the RASHBA who says that according to this reasoning, there is a difference between a person who gives a loan and a person who entrusts a deposit with a guardian. One who gives a loan does a favor for the borrower, and thus the borrower must comply with any conditions made afterwards. One who entrusts an item with a guardian cannot make any conditions after the item has been handed over, because he does not benefit the guardian in any way by giving over the item.
(b) The Magid Mishneh quotes the RAMBAN who says that if the borrower does not accept the lender's condition made after the loan, he is not obligated to return the money in front of witnesses. The Mishnah here refers specifically to a case in which the borrower agrees to the condition (or says nothing at the time the condition is stated). The Ritva also quotes this opinion in the name of the RE'AH and concurs with it.
(c) The ROSH (6:11) and others give an explanation similar to that of the Ramban. However, they argue that if the borrower does not explicitly agree to the condition, he does not have to pay back in front of witnesses.
(d) The RAN (20b of the pages of the Rif, and as cited by the KESEF MISHNEH, Hilchos Malveh v'Loveh 15:1) answers that the reason why the borrower must pay back in front of witnesses is not that the demand of the lender creates an obligation on the borrower. Rather, if the lender warned the borrower to repay only in front of witnesses and the borrower later argues that he returned the money without witnesses, there is an "Anan Sahadei" that the borrower is not telling the truth. ("Anan Sahadei" literally means "we are witnesses" and refers to a situation in which his intention is as clear to us as if he had explicitly stated it.) When a lender requests to be paid back with witnesses, the borrower certainly will be careful to pay back with witnesses.
The S'MA (CM 70:12) explains that the Ran maintains that even if the borrower says, at the time the lender expresses his condition, that he wants to pay back only without witnesses, he still must pay back with witnesses. Since the lender explicitly stated this condition, the borrower would not pay back without witnesses, because he certainly wants to remove any suspicions or arguments about his repayment. The Ran and S'ma explain that is also the position of the Rambam.
(e) However, the SHACH (CM 70:9) argues that the Rambam rules differently. If the borrower protested when the lender demanded that the loan be repaid in front of witnesses, he does not have to repay in front of witnesses. In this case, the borrower is not afraid that people will say he is lying when he pays back without witnesses, because he can argue that he relied on the fact that he protested against the lender's demand and did not accept the condition, and therefore he returned the money without witnesses.
The Shach adds that the Rambam may follow the reasoning of the Ramban (as mentioned in (b) above). Only when they both agree to the condition is the borrower bound to pay back in front of witnesses (even though the condition was made after the loan). If the borrower protests and does not accept the condition, he does not have to pay back in front of witnesses. (D. BLOOM, Y. MONTROSE)