Abu Sa’id Al Khudri said “The Apostle of Allaah(ﷺ) sent a military expedition to Awtas on the occasion of the battle of Hunain. They met their enemy and fought with them. They defeated them and took them captives. Some of the Companions of Apostle of Allaah (ﷺ) were reluctant to have relations with the female captives because of their pagan husbands. So, Allaah the exalted sent down the Qur’anic verse “And all married women (are forbidden) unto you save those (captives) whom your right hand posses.” This is to say that they are lawful for them when they complete their waiting period.
