the fear of uncertainty and non-receipt. Once the effective cause is removed, its consequent and ruling are likewise removed. If he is then unable to collect it, he has the right to rescind the sale, provided that the seller does not profit from it—that is, he does not sell it for more than he paid for it—because the Prophet, peace and blessings be upon him, forbade profiting from that for which one has not assumed liability (1), and due to the hadith of Ibn Umar, may Allah be pleased with him (2). It is also conditional that no deferred riba be involved between them. For example, if I sell him one hundred sa' of dates owed by So-and-so in exchange for one hundred sa' of barley, this is not permissible, because deferred riba is involved, and I have not taken possession of the countervalue.
The second case is selling a debt to the one who owes it.
An example is that someone owes me one hundred sa' of wheat, and he comes to me and says, “I do not have any wheat, but I will give you two hundred riyals in exchange for the one hundred sa'.” This is a sale of debt for debt, concerning which there is further detail:
If he sells it at its current market price, there is no harm; but if he sells it for more, it is not permissible. The evidence is the hadith of Abdullah ibn Umar, may Allah be pleased with him, who said: “We used to sell camels for dirhams and receive dinars in payment for them, and sell them for dinars and receive dirhams in payment for them.” We asked the Messenger of Allah, peace and blessings be upon him, about this, and he said: “There is no harm in taking it at its price on that day, so long as you do not part while anything remains outstanding between you.”
The Prophet, peace and blessings be upon him, thus stipulated two conditions:
The first condition: that you take it at its price on that day.
The second condition: that they do not part while anything remains outstanding between them.
The reason for this is that, if he takes it for more, he has profited from something that has not come under