Must a loan be repaid in front of witnesses?
When the original loan was made without witnesses, there is certainly no need for witnesses at the time of repayment. If, however, there were witnesses at the time when the loan was made, we find a difference of opinion in the Gemara. Rav Pappi quotes Rava as saying that in such a case the repayment must be made in front of witnesses, while Rav Pappa quotes Rava as saying that it does not need to be made in front of witnesses unless there was a specific condition made by the lender at the time that the loan was made. Even in such a case, if the borrower claims that he paid the loan back in front of witnesses, he will be believed even if he cannot produce them (e.g. if he says “I paid you back in front of witnesses but they have since traveled across the sea.”).
Although our Gemara concludes with Rav Pappa’s statement that the borrower would be believed to say that he paid the loan back in front of witnesses, some of the rishonim had alternative readings of the Gemara. Rabbeinu Ḥananel as well as the Ri”f and the R”i Migash had manuscripts that concluded with Rav Pappa saying that the borrower is not believed to make such a claim. On the other hand, Rav Sa’adia Ga’on has the reading that appears in our Gemara, and the Rambam claims that he found 500 year-old manuscripts in Egypt that have that reading.
The Sefer Hafla’ah suggests that that the difference of opinion on this matter stems from different understandings of the meaning of the condition that the lender made at the beginning of the loan. According to the Rambam, he simply was insisting that the repayment be made in a formal way – in front of witnesses – and if the borrower insists that he fulfilled that condition, we have no reason not to believe him. The Ri”f, however, understands that the original condition that was made showed that the borrower was not trusted by the lender, which is why he insisted on witnesses to the repayment. Thus, if the witnesses cannot be found, the borrower cannot be believed.