Is a Salam contract valid if a single currency is stipulated for subject matter consisting of two different commodities without specifying the price proportion for each?
Chapter on Guaranteed Salaf (Advance Payment) for a Specified Term
Al-Mughni
Book of Sales
Primary text
A contract where a single currency, such as one Dinar, is stipulated for two items, like a Sa' of wheat and a Sa' of barley, without clarifying the portion of the Dinar allocated to each commodity, is invalid. The reasoning is that the counter-value for each commodity is unknown, rendering the contract invalid, just as if a single commodity were contracted for with an unknown price. Moreover, this involves undue risk (gharar) because if one commodity becomes impossible (to deliver), it is unknown how to prorate the return based on the remaining portion. This mirrors the ruling that the description and quantity of the price must be known.
Supporting text
Malik permitted this contract. Al-Shafi'i has two views mirroring the differing opinions. Some scholars argue that since a contract valid for two items in two separate contracts is valid in one contract for those two items, this should also be valid, similar to spot sales or when the price of one item is specified. Furthermore, it is argued that since it is permissible to stipulate a deferred delivery for one item using two deferred periods without specifying the price for each period, the same logic applies here.