Then, having learned through notification or admission that his capital cost was ninety, the sale is valid; for this is an addition to the price and does not prevent the validity of the contract, just like a defect. The purchaser has the right of recourse against the seller for the amount that was added to the capital, which is ten, and to deduct it from the profit, which is one dirham, leaving the purchaser with a cost of ninety-nine dirhams. This is the view of al-Thawri and Ibn Abi Layla, and it is one of the two opinions of al-Shafi'i. Abu Hanifa said: He is given the choice between taking it at the full price or leaving it, by analogy to the case of a defective item. Our argument is that he sold it to him at his capital cost and the profit he stipulated; thus, when the capital cost turns out to be a certain amount, it is sold at that amount plus the increase they agreed upon. As for a defective item, it is the same according to us; he has the right to take compensation (arsh), and as for the defective item, he was not satisfied with it except for the stated price, whereas here, he was satisfied with it at the capital cost and the stipulated profit.

Does the purchaser have an option (khiyar)? It is narrated from Ahmad that the purchaser is given the choice between taking the sold item at its capital cost and its share of the profit, or leaving it. This was transmitted by Hanbal. It is also related as an opinion of al-Shafi'i, because the purchaser is not safe from wrongdoing regarding this price as well, and perhaps he had a specific purpose in purchasing it at that exact price, such as if he were under an oath, an agent, or otherwise. The apparent implication of al-Khiraqi’s words is that he has no option, as he did not mention it. This is also related as an opinion of al-Shafi'i, because he was satisfied with it at one hundred and ten, so if he obtains it at ninety-nine, it is an increase in benefit for him, and thus he has no option, just as if he bought it assuming it was defective, then it turned out to be sound; or assuming it was unlettered, then it turned out to be a craftsman or a writer; or if he was appointed to purchase a specific item for one hundred, and he purchased it for ninety. As for the seller, he has no option, because he sold it at his capital cost and its share of the profit, and he has obtained that.

Section: If one wishes to inform [the purchaser] of the price of the merchandise, and it is in its original state, unchanged, he informs him of its price. If the seller reduces some of the price for the purchaser, or increases it for him after the contract has become binding, it does not suffice; he must inform [the new buyer] of the first price, and nothing else, because that [reduction or increase] is a gift from one of them to the other and cannot be considered as compensation. This is the view of al-Shafi'i. Abu Hanifa said: It is attached to the contract, and he informs [the buyer] of it.