What are the essential descriptive conditions for the object of a forward sale (Muslam Fih)?
Chapter on Guaranteed Salaf (Advance Payment) for a Specified Term
Al-Mughni
Book of Sales
Primary text
The object of the forward sale must be specified by its attributes, as the amount due is against one's liability (Dhimmah). Certain attributes are universally agreed upon as necessary for specification: the genus, the species, and the quality (goodness or poorness). There is no known disagreement among scholars regarding the necessity of these three attributes, and this is the position of Abu Hanifa, Malik, and Al-Shafi'i. Specification is required either by sight or by description; since sight is impossible in a forward sale, description is necessitated.
Supporting text
Abu Hanifa opines that mentioning these three agreed-upon attributes suffices because they implicitly cover other attributes. However, the correct view is that other attributes affecting price, such as color or region, must also be mentioned, similar to the species.