QUESTION: The Mishnah later (20a) states that if one finds any document authorized by Beis Din he may return it to the bearer. The Gemara here says that this refers to a Shtar "Chaltasa" and a Shtar "Adrachta," documents which give permission to a creditor to seize the possessions of a debtor. These documents may be returned to the creditor; the Gemara is not concerned that the creditor may have collected the property of the debtor already and that the debtor redeemed his property by paying money to the creditor, and now the creditor seeks to use the Shtar again to collect from the debtor unlawfully. The Gemara assumes that if the debtor indeed had redeemed his property, he should have demanded either that the Shtar Adrachta be torn up or that the creditor write a normal Shtar Mechirah (bill of sale) for the land that he redeemed. Since the debtor did neither of these two things, he is considered to have caused his own loss.
In contrast, a Shtar Halva'ah (deed of loan) that was found may not be returned to the lender. In that case, the Gemara is concerned that the borrower may have already paid back the debt, but he was unable to retrieve the Shtar and tear it up, either because the lender told him that he would give it back the next day ("Ishtamutei") or because the lender wanted to hold on to the Shtar until the borrower reimbursed him for the scribe's fees.
Why does the concern that the lender eluded giving back the Shtar apply only in the case of a loan? Even in the case of a Shtar Adrachta, when the borrower demands the return of the Shtar the lender can push him off and say that he will give it to him the next day. Thus, it would not be the borrower's fault that the Shtar was not destroyed, and in the case of a Shtar Adrachta the Gemara should rule that the Shtar Adrachta not be returned to the lender because the property may have been redeemed already.
Similarly, just as the Gemara reasons in the case of a Shtar Adrachta that the lender caused himself a loss by not demanding that a new Shtar be written, the Gemara should apply the same logic to a Shtar Halva'ah. In that case, too, when the borrower repaid the loan, he should have demanded that the lender write a receipt. Why is the case of a Shtar Halva'ah not considered a case in which the borrower brought the loss upon himself? (RISHONIM)
(a) The RAN differentiates between the two cases. In the case of a Shtar Halva'ah, the borrower is not expected to demand that a receipt be written when he repays the loan. He prefers to receive the original Shtar from the lender and tear it up rather than receive a receipt which he will be bound to protect from destruction by rodents. Hence, the borrower agrees to wait for the lender to return the Shtar Halva'ah to him. In contrast, in the case of a Shtar Adrachta, the borrower has no reason to prefer to have the Shtar returned to him rather than to have a new Shtar Mechirah written; in either case he will have to hold onto and protect the Shtar. (If he receives the Shtar Adrachta in return and tears it up, he still will need to keep the fragments of it in case the lender brings witnesses to testify that the land was legally confiscated from the borrower and became his property. In such a case, if the borrower does not have the torn Shtar Adrachta as proof that he redeemed the land from the lender, he will be forced to return the land.) Hence, the Gemara says that if he neither demanded that the Shtar Adrachta be returned to him nor demanded that a new Shtar Mechirah be written, he is considered to have caused a loss to himself.
(b) The MAHARSHAL answers that in the case of a Shtar Adrachta, it is not possible for the lender to evade giving back the Shtar. Evading the return of the Shtar is a possibility only in the case of a Shtar Halva'ah. This is because in the case of a Shtar Halva'ah there is a relationship of trust between the borrower and the lender, so that when the borrower pays back the loan he trusts that the lender will return the Shtar to him later. In contrast, when a borrower has refused to pay back the loan and the lender has been forced to confiscate his property, there obviously is no longer any relationship of trust between them, and thus the borrower certainly will not give money to the lender to redeem his land without receiving the Shtar Adrachta in return; he will not trust the lender to give him the Shtar later.