How is dried bread, once crushed into crumbs (futeet), to be exchanged?
Chapter on Riba (Usury) and Exchange (Sarf)
Al-Mughni
Book of Sales
Primary text
If bread is dried and then crushed into crumbs, it must be exchanged by measure (kail) equal to its like, because measurement has become possible, and the item has reverted to a form where measurement is the established standard.
Supporting text
Ibn Aqil mentioned an alternative view that it should be exchanged by weight because it has changed form to one typically sold by weight.