Is Salam valid for commodities that are intended mixtures whose components are indistinguishable?
Chapter on Guaranteed Salaf (Advance Payment) for a Specified Term
Al-Mughni
Book of Sales
Primary text
Salam is invalid for items that consist of intended, non-distinguishable mixtures, such as high-grade perfumes (*ghaliyah*), incense (*nudd*), and medicinal pastes (*ma'ajin*), due to the impossibility of defining them precisely by specification. Likewise, Salam is invalid for pregnant animals because the offspring is unknown and not yet existent, and for vessels whose heads and middles vary, as the specification cannot cover such differences.
Supporting text
There is an alternative view suggesting Salam is valid for vessels if defined by the height of their walls and the circumference of their top and bottom, as the variation in these is minor. Another view permits Salam for bows (*qasi*) composed of various materials like wood, horn, and specific woods because controlling the exact measure and differentiation of these components is difficult, though the preferred opinion is that it is invalid. A distinction is made regarding mixtures: Salam is valid if the mixture is intended and distinguishable (like cloth woven from cotton and linen) or if the mixture is added for the benefit of the primary item and is minor (like rennet in cheese or salt in dough). Salam is invalid if the mixture is non-intended and serves no purpose, such as milk adulterated with water.