22وَلا تَنكِحوا ما نَكَحَ آباؤُكُم مِنَ النِّساءِ إِلّا ما قَد سَلَفَ ۚ إِنَّهُ كانَ فاحِشَةً وَمَقتًا وَساءَ سَبيلًاBijan MoeinianIt is a sin to marry your father’s ex-wife (a shameful and disgusting tradition of the days of ignorance) unless it has happened before the revelation of this law.