Sa’if 3, Mechaber: A borrower comes to court of his own accord, without being sued. He volunteers the following information: One of two named people lent him a maneh but he does not remember which of them lent him the money. He is exempt from payment altogether. He does not even have a moral obligation to pay. Some, however, are of the opinion that he does have a moral obligation to pay a maneh to each.
Ner Eyal: According to the first opinion cited above, the opinion of the Ramban, the borrower has no moral obligation to pay because none of the parties involved are certain about the facts. The borrower does not remember whom he borrowed from. The lenders are not certain either. That is why they did not sue. The rule is that where no party is sure of the facts, the money stays where it is. The only exception to this rule is where the person who has possession of the money obtained it illegally or was otherwise at fault. Such would be the case where he stole the money or was negligent in not remembering who lent him the money.
Why is the halacha in this case different from the halacha discussed previously in Siman 75? There we saw that if the plaintiffs themselves are not certain which of them lent two hundred dinarim and which of them lent one hundred dinarim, the defendant has a moral duty to pay the additional one hundred dinarim. Why, then, is the borrower discussed in this Sa’if not morally bound to pay both persons where he cannot remember which of the two he borrowed from?
There are several answers to this question. In the previous case discussed in Siman 75, the defendant knew he borrowed from two different people and should have made a note of who gave him what. He should have anticipated that the plaintiffs themselves might later forget who gave what. Here, however, the borrower only borrowed from one person. He could not anticipate that he would later forget whom he borrowed from.
Another answer is that in the case mentioned in Siman 75, the lenders heard from the borrower himself that each one of them lent him money. This is a concrete admission that the borrower owes something to both. Therefore, they can reasonably expect the borrower will remember how much he borrowed from each. In this case, however, all they hear from the borrower is that one of them lent him money and that he does not know which one. There is nothing concrete about this admission. There is total doubt about all relevant facts. Therefore the default rule applies that where none of the parties involved are certain about the facts, the money stays where it is.
The other opinion quoted in this Sa’if is the opinion of the Rosh. The borrower who does not remember which of the two persons he borrowed from does have a moral obligation to pay one hundred dinarim to each. That is because this case is similar to the situation discussed in the Mishnah in Bava Metzia 37a. In that case a person volunteered, without being sued, that the father of one of two people deposited money with him for safekeeping. However, he could not remember which of the two fathers made the deposit. The Mishnah rules that he must pay both of them because he was more to blame than the other parties involved. He should be expected to remember whose father deposited money with him. According to the Rosh, there is no difference here between a deposit and a loan and the same result would apply in the case of the loan discussed in this Sa’if.