If, in a spot exchange of currency, part of the consideration is taken possession of while part is deferred (that is, an exchange stipulated to be hand-to-hand), one opinion holds that the entire transaction is void; this is the view of al-Shāfiʿī. A second opinion maintains that only the deferred portion is invalid while the portion already received stands; this was stated by Abū Ḥanīfah, Muḥammad, and Abū Yūsuf, and both opinions are reported within the school.
The underlying question is this: when a single bargain contains both lawful and unlawful elements, does the presence of the unlawful element corrupt the whole bargain, or only that specific part?
The Fifth Issue
There is consensus among the scholars that murāṭalah—exchanging gold for gold or silver for silver by weight—is permissible, even when the number of pieces differs, so long as the total weight is identical and the two quantities are of the same quality.
They disagreed over murāṭalah in two situations:
- When the quality of the two amounts of gold differs.
- When one quantity of gold is lighter than the other and the other party wishes to make up the shortfall with a commodity, with dirhams when the murāṭalah concerns gold, or with gold when the murāṭalah concerns dirhams.
Mālik held—regarding the first situation, where the two portions differ in excellence and inferiority—that if one party offers a single grade of gold and the other produces two grades, one superior to that single grade and the other inferior, the transaction is impermissible. However, if the single grade presented by the first party is itself superior to both grades presented by the second, or inferior to them both, or equal to one of them yet better than the other, the murāṭalah is valid in his view.
Al-Shāfiʿī said: whenever the two kinds of gold differ in grade, the exchange is not permissible.
Abū Ḥanīfah, together with all the Kufan and Basran jurists, held that every form of such exchange is permissible.
Mālik’s rationale for prohibiting it is suspicion, which leads him to the doctrine of blocking the means (sadd al-dhariʿah). He suspects that the exchanger’s real aim is to sell the two portions of gold at a disparity: as though he gives a part of medium-grade gold for more of an inferior grade, or for less of a superior grade, thereby using this device to sell gold for gold with an excess on one side.
An example: a man says to another, “Take from me twenty-five medium dinars for twenty superior ones.” The other replies, “That is not lawful for us, but I will give you twenty superior dinars together with ten that are below the grade of yours, and you give me thirty medium dinars.” In this arrangement the ten inferior dinars correspond to five of your dinars, while the twenty medium dinars correspond to the twenty superior dinars that you receive.
Al-Shāfiʿī’s foundation is his consideration of the disparity that exists in market value.
Abū Ḥanīfah’s foundation is the presence of equal weight in the two quantities of gold and his rejection of the principle of blocking the means.
A similar disagreement appears in exchanges carried out by count rather than weight, that is, when the two portions of gold—or the various kinds of gold—differ in quality.
As for their dispute when the murāṭalah leaves a shortfall and one of the parties wishes to add something, whether of a riba-bearing commodity or one in which no riba occurs, the matter is close to the foregoing disagreement—for example, when one of them wishes to