—denominated in a specific coinage: if the ruler later replaces that coinage with another, the debtor is liable only for the coinage that bound him on the day the contracts were concluded.

Whoever borrows from a money-changer a sum of dirhams valued at a dinar or half a dinar, and the rate thereafter falls or rises, is responsible only for the same amount he took.

The Book of Usurpation discusses several cases in which jewellery is consumed and rules that its value—whether in silver or in gold—must be paid, either immediately or on deferred terms.

Mālik permits the sale of mined earth that contains gold for silver, and that which contains silver for gold, so long as the exchange is hand-to-hand; deferred payment is not allowed. All other goods, however, may be purchased for cash or on credit. According to him, it is never permissible to buy the sweepings from a goldsmith’s workshop under any circumstance.