Is Zakah due on prohibited forms of wealth used for commerce?
Chapter on Zakat on Gold and Silver
Al-Mughni
Book of Zakat
Primary text
Zakah is obligatory on wealth whose acquisition is prohibited if such wealth was created for trade or as a means to acquire other things, as the underlying ruling for Zakah remains due unless a prohibition against paying it is established. Imam Ahmad stated that Zakah is due on ornamentation found on saddles or bridles. He also affirmed that the adornment of the posterior part of the saddle (al-thifr) and the gear (al-rikab and al-lijam) is prohibited. Furthermore, if a roof is overlaid (tamwih) with gold or silver, it is prohibited, and Zakah is due upon it if it reaches the nisab.
Supporting text
The Companions of the Opinion (Ashab al-Ra'y) permitted such adornment because it is secondary to an otherwise permissible item, thus following its ruling. However, this view is refuted because it constitutes extravagance, leads to arrogance, and breaks the hearts of the poor, making it prohibited, similar to the prohibition of gold and silver vessels. The prohibition extends to adorning Qurans, prayer niches (maharib), and making lamps of gold or silver, as they are treated like vessels.