Muwatta Malik, Book 38, Hadith 20 (USC-MSA) ⓘ
Malik related to me from Abdullah ibn Dinar from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, forbade selling or giving away the wala'.
وَحَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ بَيْعِ الْوَلاَءِ وَعَنْ هِبَتِهِ .
also referenced under: Book 38, Hadith 1485 (In-Book)
Malik said that it was not permissible for a slave to buy himself from his master on the provision that he could give the wala' to whomever he wished as the wala' was for the one who set him free, and that had a man given permission to his mawla to give the wala' to whomever he wished, that would not have been permitted, because the Messenger of Allah, may Allah bless him and grant him peace, had said, "The wala' is for the one who sets free. " The Messenger of Allah, may Allah bless him and grant him peace, forbade selling or giving away the wala'. For if it was permitted to the master to stipulate that for him and to give him permission to give the wala' to whomever he liked, that would be a gift.