Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said that if a person has completely freed his slave to the extent that his testimony has become valid, his sanctity has been established, and his inheritance has been confirmed, then it is not permissible for his master to impose any condition of wealth or service upon him, nor to place any burden of slavery upon him, because the Messenger of Allah, peace and blessings be upon him, said: "Whoever frees his share in a slave, then the value of the slave should be assessed and each partner should free his share accordingly, and the slave will become free over him." Imam Malik, may Allah have mercy on him, said: Therefore, in the case where the slave is solely his property, he is more entitled to complete his freedom, and he cannot place the burden of slavery upon him.