Jewish law recognizes that formal loans that are recorded in signed contracts create liens of the property of the borrower that effectively guarantee payment of the loan. Therefore, if a borrower cannot pay back his loan, the lender has the right to take possession of real estate that was owned by the borrower at the time of the loan – even if it had subsequently been sold to a third party. Clearly the borrower will have to make amends with the purchaser, given that the sale has effectively been nullified.
In our Gemara, Abaye teaches that in a case where “Reuven” sold property to “Shimon” – and guaranteed the sale – and Reuven’s creditor came and collected the property from Shimon as payment of Reuven’s outstanding loan, it would be appropriate for Reuven to enter negotiations with the creditor. The creditor cannot claim that his interaction with Reuven has ended, and it is now up to Reuven to compensate Shimon, but Reuven has no right to engage him further. The Gemara concludes that this is even true if Reuven did not guarantee the sale to Shimon, because Reuven can argue that he does not want Shimon to have complaints against him.
The question raised by the rishonim is why this ruling is significant. What difference does it make whether it is Reuven or Shimon who argues with the creditor?
Rashi suggests that, given his previous interactions with the creditor, Reuven has a larger array of arguments that he can make. He can claim, for example, that the loan was already paid, or that there are other outstanding loans that are owed to him that would cancel the debt that is owed. Other suggestions are that Reuven can argue that there is still time before the loan comes due, or that the contract that was brought to court was forged. The Rosh brings an explanation that the Ramban says is the simplest approach to this story. According to the Rosh there is no real difference between Reuven and Shimon – either one could make the same arguments. Nevertheless, we know that some people are more talented at presenting arguments in court. If Reuven is particularly adept at presenting his case, he can take the initiative to do so, and the creditor cannot insist that only Shimon – a less talented adversary – has the right to argue in court.