Qabasوَلَا تَنكِحُواْ مَا نَكَحَ ءَابَآؤُكُم مِّنَ ٱلنِّسَآءِ إِلَّا مَا قَدۡ سَلَفَۚ إِنَّهُۥ كَانَ فَٰحِشَةٗ وَمَقۡتٗا وَسَآءَ سَبِيلًا ٢٢
Walā tankihū mā nakaha ābā'ukum minan-nisā'i illā mā qad salafa innahū kāna fāhishatan wamaqtan wasā'a sabīlā
And do not marry those [women] whom your fathers married, except what has already occurred.175 Indeed, it was an immorality and hateful [to Allāh] and was evil as a way.
Footnotes
175 Before Islām. After the ruling was revealed by Allāh, men were required to release those women unlawful to them (e.g., a stepmother, one of two sisters, or any wives over the limit of four). The same obligation applies to one once he has accepted Islām.