—whether in volume, weight, or count—is not. All of the foregoing is allowed only when no such stipulation was made at the time of the loan; once it is made conditional, none of it is permissible. The same ruling applies to foodstuffs and every other kind of merchandise: if the borrower settles the debt with something superior in quality, that is a mark of gratitude on his part and an excellent repayment. If he repays with something inferior in quality, or with less measure or weight, that is an act of forbearance on the creditor’s part and a perfect kindness.
It is not lawful to borrow Kufan dinars on condition that they be repaid with Damascene dinars, nor to borrow grain on condition that it be repaid with something different; the same prohibition covers every comparable case. Likewise, one may not advance a loan on the understanding that the lender will have a say in what the borrower hands over in repayment, or on the understanding that the borrower will confer any benefit upon the lender because of the loan, however great or small. Every increase attached to a loan or any benefit that accrues to the lender by virtue of it is usury (ribā), even if it were no more than a single handful of fodder, and it is forbidden whenever it is stipulated.
Imam Mālik considered it reprehensible for a creditor to consume the debtor’s gift unless that exchange was their normal practice before the loan, or the creditor is certain that the gift has nothing to do with the debt.
Lending and borrowing are permissible with every sort of property—movable goods, ready cash, and all kinds of livestock—except female slaves; lending or borrowing them is not allowed. Whoever borrows a slave-girl may return her so long as he has not had intercourse with her; if he does, he may no longer return her and must instead pay her owner her full value.
It is also impermissible for someone to borrow an item that entails transport and expense in one town on the understanding that he will return it in another. As for safātij (bank drafts) involving dinars and dirhams