—not, however, as a commercial exchange in which a counterfeit dirham is swapped for a sound one in some trifling amount where it is plain that the doer’s purpose is generosity and courtesy, not trade.

Ibn al-Qāsim rules that it is impermissible for a man to sell his slave to another for a sum of dinars on condition that the buyer then sells the same slave back to him for an equal, smaller, or larger amount of dinars, with both parties actually handing over the cash. If, instead, they simply set the two sums off against each other so that only the excess is paid, the transaction is allowed.

Likewise, there is no objection to exchanging merchandise and dirhams for gold when the dirhams involved are less than the silver equivalent of a single dinar and payment is immediate with nothing deferred, for combining goods and dirhams against gold is treated exactly like a straight currency exchange (ṣarf) in which no goods are present.

The purport of what the Madinan authorities transmit from Mālik on this principle is that when a small, inferior amount of silver accompanies a commodity in a deal that involves gold, the sale is valid because that silver is not the object of the bargain. If the silver portion is substantial, however, the sale is invalid: it would combine currency exchange and ordinary sale, and Mālik does not allow the two to be joined. Rabīʿah holds the same view; both scholars deem such a transaction disliked and invalid whenever the parties intentionally structure it that way.

In summary, the position of Ibn al-Qāsim—his own report from Mālik and the view adopted by most of the Egyptian Malikis—is that when one or two dinars are exchanged for goods together with dirhams, the transaction is unobjectionable so long as the dirhams fall short of the value of a full dinar. Should they equal a dinar, the deal is unsound. If the gold component is a single dinar together with goods and dirhams, Ibn al-Qāsim allows the dirhams only up to the worth of half a dinar, or less; anything beyond that renders the sale impermissible.

For Ibn al-Qāsim, the benchmark of “a dinar’s worth of dirhams” applies only when the gold side is a single dinar, whereas he tolerates less than a full dinar’s worth of dirhams when the goods are sold against several dinars, because—