Not graded
Bulugh al-Maram 1103d
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."
Cited in Bulugh al-Maram (No. 1103d).