Verily Allah and His Messenger have forbidden the sale of wine, carcass, swine and idols, It was said: Allah's Messenger, you see that the fat of the carcass is used for coating the boats and varnishing the hides and people use it for lighting purposes, whereupon he said: No, it is forbidden, Then Allah's Messenger (ﷺ) said: May Allah the Exalted and Majestic destroy the Jews; when Allah forbade the use of fat of the carcass for them, they melted it, and then sold it and made use of its price (received from it).
The Book of Musaqah - Sahih Muslim 1581a
This narration from Sahih Muslim establishes the fundamental prohibition of certain impure substances in Islamic commercial transactions, emphasizing the sanctity of divine injunctions.
Prohibited Substances in Commerce
The Prophet (ﷺ) explicitly forbade four categories: wine (intoxicants), dead carcass (maytah), swine, and idols. These prohibitions extend beyond mere consumption to include all commercial dealings, as transactions involving unlawful substances are themselves unlawful.
The wisdom behind these prohibitions lies in preserving spiritual purity, physical health, and moral integrity within the Muslim community.
Clarification on Carcass Fat Usage
When companions inquired about potential permissible uses of carcass fat for practical purposes like boat coating, hide varnishing, or lighting fuel, the Prophet (ﷺ) maintained the absolute prohibition.
This demonstrates that the prohibition encompasses all forms of utilization, regardless of transformation or intended purpose, preserving the comprehensive nature of the divine injunction.
Condemnation of Legal Evasion
The Prophet's condemnation of Jewish practices regarding carcass fat illustrates the grave sin of legal circumvention (hiyal). By melting and selling the forbidden fat, they technically avoided direct consumption while violating the spirit of the prohibition.
This serves as a permanent warning against attempting to bypass divine commandments through technicalities, emphasizing that Islamic law considers both the letter and spirit of religious injunctions.
Scholarly Implications
Classical scholars derive from this hadith that any substance fundamentally prohibited cannot become lawful through transformation or change of form. The original prohibition remains attached regardless of physical alteration.
Furthermore, income derived from unlawful sources remains impermissible, establishing the principle that the means of earning must be pure along with the substance itself.