Chapter on Khums
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 1|Chapter 7
وَ رَوَى أَبُو عُبَيْدَةَ اَلْحَذَّاءُ عَنْ أَبِي جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: «أَيُّمَا ذِمِّيٍّ اِشْتَرَى مِنْ مُسْلِمٍ أَرْضاً فَعَلَيْهِ اَلْخُمُسُ».
Abu Ubaydah al-Haddha’ narrated from Abu Ja’far Imam Muhammad ibn Ali Al-Baqir عليه السلام who said: "Any non-Muslim under the protection of Islam (dhimmi) who buys land from a Muslim is obligated to pay Khums on it."
- Ṣaḥīḥ al-Faqīh, p. 85