Narrated Ibn 'Umar: Allah's Messenger ﷺ forbade the selling or donating the Wala' of a freed slave.
The Prophet Muhammad (peace be upon him) was very clear on this point as he wanted everyone to be treated fairly and justly in all matters related to freedom from slavery. He also wanted people who were formerly slaves not to suffer any financial loss due to their emancipation from slavery but rather benefit from it instead. This hadith teaches us that we should always strive for justice in our dealings with others no matter what our relationship with them may be like.