Al-Kāfi - The Book of Commerce

Al-Kāfi - The Book of Commerce Chapter: Rule about Unlawful Interest ِنْ أَصْحَابِنَا عَنْ أَحْ٠َّدِ بْنِ عِيسَى عَنِ ابْنِ أَبِي عُ٠َيْرٍ عَنْ هِشَا٠ٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلا٠ِنْ سَبْعِينَ زَنْيَةً كُلُّهَا بِذَاتِ ٠1.

A number of our people have narrated from Ahmad ibn Muhammad ibn ‘Isa from Ibn Abi ‘Umayr from Hisham ibn Salim that Abu ‘Abdillah (al-Sadiq) (as) said, “The sin of receiving one dirham of [unlawful] interest is more serious than having seventy carnal relations with one’s mahrams." صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (19/122))