Musannaf Ibn Abi Shayba 9:985

'Abd al-A'la narrated to us, from Sa'id, from Qatada, from Abu al-Khalil, that Abu 'Alqama al-Hashimi narrated to them that Abu Sa'id al-Khudri narrated to them that the Prophet (ﷺ) sent a military detachment on the day of Hunayn. They encountered a tribe of the Arabs on the day of Awtas, so they defeated them and killed them, and they captured women of theirs who had husbands. Some of the companions of the Prophet (ﷺ) felt hesitant about having intercourse with them because of their husbands. Then Allah revealed: "And [also prohibited are] women already married, except those your right hands possess." [This was] regarding them, so they became lawful for you.