a house from you for one hundred riyals, then I have now leased a specified item in exchange for something owed as a liability. This is not called a sale, because it is not in perpetuity. Thus, a sale must be permanent. Hence, if someone were to say, “I sold this house for one year for one thousand riyals,” this contract would not be valid as a sale, because it is not in perpetuity.

Would it be valid as a lease? This rests upon a well-known principle among the jurists: “If a contract is described in a manner contrary to what was agreed upon, is it to be construed in its valid form, or is it to be invalidated altogether?” There is a difference of opinion on this.

His statement, “not usury”: usury is not called a sale, even though an exchange takes place in it. Thus, if I give you one dirham for two dirhams, it is one specified item for another; yet it is not a sale. What excludes it from being a sale?

The answer is that Allah has made it a separate category from sale, and that which is juxtaposed with something is not the thing itself. Allah says: “Allah has permitted trade and forbidden usury.” [al-Baqarah: 275] Thus, usury is not a sale; otherwise, this distinction would not be sound.

His statement, “and not a loan,” means that a loan likewise is not called a sale, even though an exchange takes place in it.

For example, a wealthy person may come to someone who has asked him for a loan and say, “Take these dirhams; I am lending them to you.” The dirhams are now specified, while the loan is owed as a liability. It therefore resembles an exchange of specified property for property owed as a liability, but it is not called a sale. For if it were a sale, loans involving usurious commodities would be invalid.

For example, if I sold you one dirham for one dirham, but did not take possession of it from you until two days later, this would be usury.

But if I lent you one dirham, to be returned to me after two days, that is permissible.