As for what is claimed to be contrary to analogy, we say that it accords with analogy, and we shall explain how. Or we may say that it departs from analogy due to a preponderant benefit. When a legal prohibition is counterbalanced by a benefit that outweighs it, it becomes permissible because that benefit is preponderant. If the Sacred Law prohibits something because its harm is greater, then it permits something when its benefit is greater. Hence the well-known maxim, “Averting harms takes precedence over procuring benefits,” must be qualified to cases in which harms and benefits are equal, or in which the harmful aspect predominates. Otherwise, something may involve both benefit and harm, yet its benefit may outweigh its harm, and it is therefore deemed lawful on account of that preponderance.
Likewise, salam can be precisely defined through its specifications; this is why it is not valid in matters that cannot be precisely defined by specifications. So how can it be valid while being contrary to the legal principles and to analogy? Rather, it is in accordance with both analogy and the legal principles, for Islamic law is broad, easy, and accommodating. From this perspective, contracts fall into four categories:
Immediate payment for immediate delivery; deferred payment for deferred delivery; deferred payment with immediate delivery of the commodity; and immediate payment with deferred delivery of the commodity.
The first is immediate payment for immediate delivery, such as saying: “I bought this book from you for ten riyals.” This is immediate for immediate, and there is no issue with it.
The second is deferred payment for deferred delivery: for example, to say, “I bought from you a book with such-and-such specifications, which you will deliver to me after one year, for ten riyals deferred for six months.” This is not valid, because it is the sale of a deferred obligation for a deferred obligation—that is, one deferred item for another deferred item.
The third is where the price is paid immediately and the commodity is deferred; this is salam.