and others, who therefore saw nothing wrong with it until leading Companions—such as ‘Ubādah ibn al-Sāmit, Abū Sa‘īd, and others—informed them that the Prophet, may Allah bless him and grant him peace, had prohibited interest through unequal exchange.

As for contractual uncertainty, it is of three kinds. The first concerns something nonexistent, such as selling the future offspring of an unborn animal or selling crops for future years. The second concerns something that cannot be delivered, such as a runaway slave. The third concerns something unspecified, or a specific item whose category or quantity is unknown, as when someone says, “I sell you a slave,” “I sell you whatever is in my house,” or “I sell you my slaves.”

As for a specific item whose category and quantity are known, but whose type or qualities are unknown—as when someone says, “I sell you the garment in my sleeve,” or “the slave I own,” and similar cases—there is a well-known disagreement concerning it. Prominent here is the question of selling specific goods that are not present. Three positions are reported from Ahmad concerning this.

The first is that such a sale is invalid under all circumstances, which is also al-Shāfi‘ī’s later position.

The second is that it is valid even without a description, and that the purchaser has the option to rescind the sale upon seeing the item. This is also Abū Hanīfah’s position. However, Ahmad is also reported to have held that the purchaser has no such option.

The third—and the well-known position—is that the sale is valid if the item is described, but invalid without a description, just as with generic goods owed under a contractual obligation. This is also Mālik’s position.

The harm arising from contractual uncertainty is less than that arising from interest; concessions were therefore granted in matters called for by