Chapter on Sales
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 2|Chapter 11
وَ قَالَ عَلَيْهِ اَلسَّلاَمُ: فِي اَلرَّجُلِ يَبِيعُ اَلْمَمْلُوكَ وَ يَشْتَرِطُ عَلَيْهِ أَنْ يَجْعَلَ لَهُ شَيْئاً قَالَ "يَجُوزُ".
Imam عليه السلام said regarding a man who sells a slave and stipulates upon the buyer to give him something: "It is permissible."
- Ṣaḥīḥ al-Faqīh