Chapter on Khums
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 1|Chapter 7
وَ فِي تَوْقِيعَاتِ اَلرِّضَا عَلَيْهِ اَلسَّلاَمُ إِلَى إِبْرَاهِيمَ بْنِ مُحَمَّدٍ اَلْهَمَذَانِيِّ: «إِنَّ اَلْخُمُسَ بَعْدَ اَلْمَئُونَةِ».
In one of the writings of al-Ridha (Imam Ali ibn Musa al-Ridha عليه السلام) addressed to Ibrahim ibn Muhammad al-Hamadhani, it is stated: "Khums is due after deducting expenses."
- Ṣaḥīḥ al-Faqīh