Is a sale valid if the agent sells for an entirely different form of currency or a mix of currency and non-currency items?
General Chapter
Al-Mughni
Book of Agency
Primary text
If the agent sells for one hundred dinars instead of dirhams, or for ninety dirhams and ten dinars, or if the entire price consists of a garment or eighty dirhams and twenty garments, the sale is invalid. This ruling is stated by Al-Qadi. This aligns with the school of Al-Shafi'i because the agent contravened the principal regarding the nature (genus) of the price, similar to selling for a garment valued above the specified price.
Supporting text
There is a possibility that the sale is valid if the agent substitutes dirhams for dinars, or part of the dirhams for dinars, as this substitution is customarily permissible. Customarily, one who accepts a dirham accepts a dinar in its place, making it equivalent to selling for one hundred dirhams and a dinar. However, selling primarily for garments is invalid because garments are not of the genus of currency.