Bulugh al-Maram 8 Marriage كتاب النكاح 165

وَفِي لَفْظٍ لِمُسْلِمٍ, قَالَ اَلزُّهْرِيُّ: { وَلَا أَرَى بَأْسًا أَنْ تَزَوَّجَ وَهِيَ فِي دَمِهَا, غَيْرَ أَنَّهُ لَا يَقْرَبُهَا زَوْجُهَا حتَّى تَطْهُرَ 1 } . 1 – مسلم ( 2 / 1122 ).

A wording by Muslim has: az-Zuhri said, “I think there is no harm if she marries when she is still bleeding (due to child-birth), but her husband should not go near her till she is purified.”