Musnad Ahmad 795:10

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from Qatadah, from al-Hasan, from Qabisah ibn Hurayth, from Salamah ibn al-Muhabbaq, who said: The Messenger of Allah, peace and blessings of Allah be upon him, decreed regarding a man who had intercourse with his wife’s slave girl: "If he forced her, then she is free, and he owes her mistress the like of her."