for other goods sold by weight, such as exchanging silk for cotton or flax. If goods sold by measure are exchanged for other goods sold by measure in an unrestricted sale, such that possession of the countervalue is not taken during the session, this is impermissible. This differs from exchanging them for an animal or real estate: according to the sounder of the two views within the school, possession of these need not be taken during the session. This is also Ahmad’s explicitly stated position. His words can therefore be understood on this basis, and his prohibition of the sale should be interpreted accordingly.

For this reason, he said:

“When the debt falls due, he may purchase from him something that is sold neither by measure nor by weight.”

He thus permitted this without qualification. Goods sold by measure or weight, however, may not be purchased without qualification; rather, possession must be taken during the session, just as when they are sold in exchange for a specific asset. This interpretation is supported by Ahmad’s adherence to Ibn Abbās’s statement on this matter. Ibn Abbās said:

“If you pay in advance for something under a salam contract, and the due date arrives but you cannot obtain what you contracted for, take a substitute for less, and do not profit twice.”

The profit he prohibited was specifically that obtained by selling the debt arising from the salam contract to the debtor for more than its value at the time of settlement. This is why Ahmad prohibited taking an excess when accepting goods sold by measure—such as barley—in settlement of it. Ibn Abbās made no distinction between selling it for goods sold by measure or weight and selling it for anything else.

This is not a matter of usury through unequal exchange, such that one could object: “Ibn Abbās permits usury through unequal exchange.” Rather, selling gold for silver on a deferred basis is forbidden by the consensus of the Muslims, as is selling wheat for barley on a deferred basis. This is what follows from the principles of Ahmad’s school and those of others: what is owed as a debt is considered to be in possession. Thus, if it consists of goods sold by measure or weight, and he exchanges it for goods sold by measure or weight without taking possession of the latter, then he has exchanged goods sold by measure for goods sold by measure without taking possession. If, however, he takes possession, this is permissible.