Pour rappel :

Vous sont interdites les dames (qui ont un mari), sauf si elles sont vos esclaves en toute propriété. 4:24

tafsir :
Imam Ahmad recorded that Abu Sa`id Al-Khudri said, "We captured some women from the area of Awtas who were already married, and we disliked having sexual relations with them because they already had husbands. So, we asked the Prophet about this matter, and this Ayah was revealed,

(Also (forbidden are) women already married, except those whom your right hands possess). Consequently, we had sexual relations with these women."