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).

وَحَدَّثَنِي مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا ابْنُ جُرَيْجٍ، أَخْبَرَنِي أَبُو الزُّبَيْرِ، أَنَّهُ سَمِعَ جَابِرَ بْنَ عَبْدِ اللَّهِ، يَقُولُ كَتَبَ النَّبِيُّ ﷺ عَلَى كُلِّ بَطْنٍ عُقُولَهُ ثُمَّ كَتَبَ " أَنَّهُ لاَ يَحِلُّ لِمُسْلِمٍ أَنْ يَتَوَالَى مَوْلَى رَجُلٍ مُسْلِمٍ بِغَيْرِ إِذْنِهِ " . ثُمَّ أُخْبِرْتُ أَنَّهُ لَعَنَ فِي صَحِيفَتِهِ مَنْ فَعَلَ ذَلِكَ .