wool and milk, or selling a sword containing a small amount of silver for another sword or something else, or a house gilded with gold for another house, and similar transactions. Here, the sound view in the schools of Mālik and Ahmad is that this is permissible. The same applies when the intended transaction is an exchange between an item subject to the rules of ribā and one that is not, such as selling the house, the sword, or similar items for gold; or when an item is exchanged for its own kind in equal amounts. The case of the debased dirhams used in our time belongs to this category: the silver content of one dirham is equal to that of the other, while the copper is merely incidental and not intended in its own right. Thus, the sound view is that this is permissible.

This differs from the third category, in which both components are intended in their own right. Examples include exchanging a mudd of ʿajwa dates and a dirham for a mudd of ʿajwa dates and a dirham, or for two mudds of dates, or for two dirhams; exchanging a dinar for half a dinar and ten dirhams; or exchanging ten dirhams and a ratl of copper for ten dirhams and a ratl of copper. Such transactions are the subject of a well-known disagreement. Abū Hanīfa permits them, while al-Shāfiʿī prohibits them. Two positions are reported from Ahmad, while Mālik distinguishes between one-third and other proportions.