Sayyidina Jabir (RA) reported that a man of the Ansar assured his slave that he would he free upon his death. When he died, he left nothing in legacy save the slave. The Prophet ‘ sold him to Nuaym ibn Naham. Sayyidina Jabir (RA) said further that the slave was a qubti (copt) and died during the first year of the rule of Ibn Zubayr .
[Bukhari 1084, Muslim 997