Shu'bah bin al-Hajjaj شعبة بن الحجاج · The Book on Marriage

The Prophet said: "Whichever slave gets married without the permission of his owner, then he is a fornicator."

"We got some captives on the day of Awtas, and they had husbands among their peopled. They mentioned that to the Messenger of Allah, so the following was revealed: And women who are already married, except those whom your right hands posses.