(5) باب تَحْرِيمِ تَوَلِّي الْعَتِيقِ غَيْرَ مَوَالِيهِ
Jabir b. Abdullah (Allah be pleased with them) reported that Allah's Apostle (ﷺ) made it obligatory for every tribe (the payment) of blood-wit; he then also made it explicit that it is not permissible for a Muslim to make himself the ally (of the slave emancipated by another) Muslim without his permission. He (the narrator further added):
I was informed that he (the Holy Prophet) cursed the one who did that (and it was recorded) in his Sahifa (in a document).
Reference: Sahih Muslim 1507
In-book reference: Book 20, Hadith 21
USC-MSA web (English) reference(deprecated numbering scheme): Book 9, Hadith 3598