The sixth: the option arising in a sale based on disclosure of the price, when it proves to be lower or higher. It applies to tawliyah (resale at cost), shirkah (sale of a share at cost), murabahah (resale at a stated markup), and muwadha'ah (resale at a stated discount). In all of them, the buyer must know the capital cost.
His statement, “The sixth,” means: the sixth of the categories of option.
His statement, “the option in a sale based on disclosure of the price”: “based on disclosure of the price” modifies “sale,” not “option.” That is, it applies when he sells it after disclosing its price. Disclosure means informing, for it is the verbal noun of khabbara, “to inform,” just as akhbara, “to inform,” has the verbal noun ikhbar, “informing.”
It appears—and Allah knows best—that the jurists, may Allah have mercy on them, passed this expression down from one another: the earlier scholar used it, and those after him followed suit. Otherwise, it would have been clearer to say: “An option is established when he informs him of the price.” That is, if he sells an item and the buyer asks, “How much is the price?” and he replies, “The price is one hundred riyals,” selling it to him at its capital cost, he has then informed him of the price—that is, that the capital cost is one hundred riyals. If it then becomes clear that the capital cost was ninety riyals, the buyer has the option because the seller informed him of the price. It has become clear that his disclosure of the price was incorrect, for he said one hundred, but it was established that he had bought it for eighty.
Another example: A man came to me and said, “I bought a car for eighty thousand.” Then another man came to me and said, “Sell it to me at its capital cost.” I said, “I have sold it to you at its capital cost.” He asked, “How much is the capital cost?” I replied, “One hundred thousand.” He said, “I accept.” Later, it became clear that the price had been eighty thousand. The seller, then, lied to the buyer by giving him untrue information.
The reason the buyer is granted the option is the false disclosure of the price, because the seller gave him false information concerning the price of this commodity. This is a form of cheating and deception: he portrayed the commodity as having a high price when in reality it had a low price. This is unlawful, and for this reason the buyer is given the option.