sa‘ and ten sa‘, then this is not permissible, because it is profit from something that has not entered into his liability.

But if he says, “You are poor; give me eighty sa‘ instead of the one hundred dirhams,” this is permissible, because it is regarded as an act of kindness on his part, since he has accepted only part of his right. His entitlement was one hundred sa‘, but he chose eighty sa‘. Thus, the author’s statement, “The sale of a debt for a debt is not valid,” is not unrestricted; rather, it requires further distinction. Ibn ‘Umar’s hadith (1) is therefore the criterion in this matter—that is, concerning the sale of a debt to the one who owes it.

As for selling a debt to someone other than the debtor, it is not permissible except to someone able to recover it. However, if we say that it is permissible when he is able to recover it, the debtor must have acknowledged the debt. If he denies it, and someone comes and says, “I wish to buy the debt that So-and-so owes you, even though he denies it and has not acknowledged it; nevertheless, I am willing to take the risk, purchase it, and sue him before the judge,” this is not permissible, because it involves risk. Rather, we are speaking of selling a debt owed by someone who acknowledges it to a person capable of recovering it. The sound view is that this is permissible, because there is no evidence prohibiting it, and the basic principle is that sale is lawful, as Allah the Exalted says: “Allah has permitted trade and forbidden usury.” [al-Baqarah: 275]