the benefits of this house. The evidence is the Prophet’s statement, peace and blessings be upon him: “When two men enter into a sale.” (1) The manner in which it indicates this is as follows: a lease either falls under the hadith by its literal generality, or it falls under it by its general meaning. If a lease is a sale, then it falls under the literal generality; and if it has the meaning of a sale but is not itself a sale, then it falls under the general meaning, for there is no difference between it and a sale: both are contracts of exchange.

His statement: “and currency exchange,” means that it is also established in currency exchange, because currency exchange is a sale, though it is a particular type of sale involving monetary currencies. Thus, selling gold for silver is currency exchange, whereas selling gold for iron is not currency exchange. The scholars, may Allah have mercy on them, have assigned currency exchange its own chapter and rulings because it differs from other types of sales; hence, they mentioned it specifically. Otherwise, it is included under sale, due to the Prophet’s statement, peace and blessings be upon him: “Gold for silver is usury, except hand to hand.” (2)

His statement: “and forward sale.” The option of the session is established in a forward sale. A forward sale is for a person to hand over dirhams to the seller while deferring delivery of the commodity. For example, a man may say to a farmer: “I wish to buy from you fruit to be delivered after one or two years for one thousand dirhams; here are the one thousand dirhams.” This is called a forward sale, and it is also called an advance payment; both terms are correct. It is called a forward sale because the buyer hands over the price, and it is called an advance payment because he pays it in advance. The term advance refers to that which comes before; hence we say, the righteous predecessors, because they came before us. Thus, the option of the session is established in it.