Jabir bin Abdullah reported,

The Prophet ﷺ decreed in writing that each clan was responsible for paying its own blood-money. He then wrote that it is not lawful for a Muslim to take as patron the freed slave of another Muslim without his permission. I was further informed that in his document he cursed anyone who did so.

Muslim 3790

Sahih

و حدثني محمد بن رافع حدثنا عبد الرزاق أخبرنا ابن جريج أخبرني أبو الزبير أنه سمع

جابر بن عبد الله يقول

ا كتب النبي ﷺ على كل بطن عقوله ثم كتب أنه لا يحل لمسلم أن يتوالى مولى رجل مسلم بغير إذنه ثم أخبرت أنه لعن في صحيفته من فعل ذلك

مسلم 3790صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Emancipation of slaves
Chapter
Prohibition of a freed slave taking patrons other than his own
Numbering
Darussalam 3790
Muslim 3790