عَنْ سَلَامٍ يَعْنِي ابْنَ عَبْدِ اللَّهِ عَنِ ابْنِ عُمَرَ أَنَّهُ طَلَّقَ امْرَأَتَهُ وَهِيَ حَائِضٌ فَسَأَلَ عُمَرُ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ فَقَالَ: ((مُرْهُ فَلْيُرَاجِعْهَا ثُمَّ لِيُطَلِّقْهَا طَاهِرًا أَوْ حَامِلًا))
It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he divorced his wife while she was in her menstrual period. When Sayyiduna Umar (may Allah be pleased with him) asked the Noble Prophet (peace and blessings be upon him) about this, he (peace and blessings be upon him) said: Tell Ibn Umar to take her back, and then divorce her when she is in a state of purity or is pregnant.