What is the ruling on exchanging heterogeneous Dirhams (some copper and some silver) for pure silver Dirhams?
Chapter on Riba (Usury) and Exchange (Sarf)
Al-Mughni
Book of Sales
Primary text
It is not permissible to execute this exchange until the copper and silver components are clearly separated. Fifteen narrators affirmed this position concerning Abu Abdullah (Ahmad), with the exception of Al-Maimuni and another narration from Mihna.