6 – The Book of Sales
A sale contract is concluded by offer and acceptance, provided both are expressed in the past tense.
If one of the two parties issues the offer, the other is free to choose: he may accept it during the same session, or he may reject it. Should either of them rise from the session before acceptance, the offer lapses. Once offer and acceptance are completed, the sale becomes binding, and neither party may rescind it except on account of a defect or because the goods have not been seen. As for the counter-values mentioned earlier, the validity of the sale does not depend on their exact amount being known, whereas an unspecified price is not valid unless its amount and quality are defined.
A sale may be concluded for an immediate price or for a deferred price, so long as the term is specified. If the price is stated without further detail, it is understood to be payable in the currency most commonly used in the locality; but if several currencies circulate there, the sale is invalid unless one of them is specified.
Foodstuffs and grains may be sold by measure, by estimation, in a specific container whose capacity is unknown, or by the weight of a particular stone whose weight is unknown. Whoever sells a heap of grain saying, “each qafiz for one dirham,” the sale is, according to Abū Ḥanīfah, valid with respect to one qafiz only, unless he specifies the total number of qafizes. Whoever sells a flock of sheep on the basis of “each sheep for one dirham” makes the entire sale invalid; the same ruling applies to one who sells a length of cloth by cubits—“each cubit for one dirham”—without stating the total number of cubits.
If someone purchases a heap of grain described as one qafiz for one hundred dirhams and then finds it to be less, the buyer may choose: he may take what is present for its proportional share of the price, or he may rescind the sale. If he finds it to be more, the excess belongs to the seller.
Whoever buys a garment described as ten cubits for ten dirhams, or land described as one hundred cubits for one hundred dirhams, and then discovers it to be less, likewise has the option: he may accept it for the full price, or he may abandon it. If he finds it to be more than the stated cubits, the excess is his and the seller has no option.
If the seller says, “I have sold it to you on the basis that it is one hundred cubits for one hundred dirhams, each cubit for one dirham,” and it is then found to be deficient, the buyer again has the option: if he wishes, he may take it for its proportional price, or he may leave it; and if he finds it