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 ‏.‏

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'. Translation Not Available

Book Ref: Muwatta Imam Malik Book 38 Hadith 1485
Web Ref:  Muwatta Imam Malik Book 38 Hadith 20