What is prohibited is disposing of specified consideration. As for consideration that remains a debt obligation, the purchaser is free to dispose of it until he delivers it to the seller.

In the example I mentioned: “I bought this watch from you for ten riyals,” while intending to pay for the watch with the ten riyals in his pocket—may he dispose of these ten riyals?

The answer is: yes. But if he said, “with these ten riyals,” and then put them in his pocket, he may not dispose of them. Once the contract has been concluded upon the particular consideration itself, it becomes the seller’s property merely by the conclusion of the contract, just as the item sold, upon which the contract was concluded, becomes the purchaser’s property merely by the conclusion of the contract.

Can the item sold be a debt obligation?

The answer is: yes, it can. In a salam contract, the Companions would pay in advance for fruits to be delivered one or two years later (1), and it is known that such fruits are a debt obligation. Thus, both the price and the item sold may be a debt obligation. Whatever remains a debt obligation may be disposed of by the one responsible for it as he wishes; but whatever is specified may not be disposed of by the one from whom its ownership has passed. Thus, the purchaser may not dispose of the price, and the seller may not dispose of the item sold.

His statement, “and its consideration,” includes cases where the consideration is currency, as when one says, “I bought this house with these dirhams,” as well as where it is something other than currency, as when one says, “I bought this house with this car.” This is why the author said, “with its consideration,” rather than “with the specified dirhams,” so as to include cases where the consideration is dirhams or other specified items.