the Quran and the Sunnah. Muslims have differed over some questions concerning this. The same applies to transactions such as sales, leases, agency agreements, partnerships, gifts, endowments, bequests, and other dealings involving contracts and transfers of possession. Justice in these matters is the mainstay of human life; well-being in this world and the Hereafter depends upon it.

Some requirements of justice in these matters are obvious and recognizable to everyone through reason: the buyer’s obligation to pay the price; the seller’s obligation to deliver the purchased goods to the buyer; the prohibition against giving short measure or weight; the obligation to be truthful and disclose relevant information; the prohibition of lying, betrayal, and deception; and the principle that a loan calls for repayment and gratitude. Other requirements are less apparent and have been laid down in the revealed laws, or in our own law as Muslims.

The transactions prohibited by the Quran and the Sunnah generally fall under securing justice and forbidding injustice, whether minor or major. These include consuming wealth wrongfully, with usury and gambling among its forms, and the kinds of usury and gambling prohibited by the Prophet, may Allah bless him and grant him peace: sales involving uncertainty; habal al-habalah sales; selling birds in the air or fish in the water; sales with an unspecified payment deadline; selling livestock whose milk has been retained in their udders; sales involving concealment; mulāmasah (sales by touching); munābadhah (sales by tossing); muzābanah; muhāqalah; sham bidding; selling fruit before its soundness becomes apparent; and the forms of partnership that he prohibited