Musannaf Ibn Abi Shayba 9:1004

Ghundar narrated to us, from Ibn Jurayj, from ‘Ata’ regarding the saying of Allah, "And [also prohibited to you are] all married women except those your right hands possess." He said: "Adultery." Mujahid said: "It is adultery." Ibn ‘Abbas said: "It is adultery." Regarding "except those your right hands possess," a man may take the slave-girl of his slave and have intercourse with her if he wishes. Others said: "They are the captives of the enemy."