We have discussed at length “the principle of invalidating legal stratagems and blocking the means to unlawful ends” in a substantial, separate work. There we established the position of the people of Medina on the basis of the Quran, the Sunnah, and the consensus of the earliest forerunners among the Emigrants and the Helpers.

The same applies to usury involving deferment. Among the people of Thaqīf, concerning whom the Quran was revealed, a creditor would approach his debtor when payment fell due and say, “Will you repay, or increase the debt?” If he did not repay, the debtor would increase the amount owed, and the creditor would extend the term. Thus the debt would multiply over time because of the deferment. This is unquestionably usury, by the consensus of the early generations of the Muslim community, and it was concerning this that the Quran was revealed. Its injustice and harm are plain.

Allah, glorified and exalted is He, has permitted sales and trade and forbidden usury. A buyer purchases something from which he can benefit, such as food, clothing, a dwelling, a mount, or other things. A merchant purchases something he intends to sell at a profit. The usurer, however, seeks only to receive money in exchange for money, with repayment deferred. The other party thus becomes liable for more than he received, without gaining any benefit; he has neither sold anything nor engaged in trade. Through his injustice, the usurer consumes wealth wrongfully and benefits people neither through trade nor otherwise. Rather, he puts out his money for an increase, without any benefit accruing to him or to others.

If this is the aim of both parties, then whatever means they use to achieve it, corruption and injustice result. An example is their agreeing beforehand that one will sell something to the other and then buy it back. This constitutes two sales in a single transaction, and in