Command him to take her back and when she is pure, then divorce her. I said to Ibn 'Umar Allah be pleased with them): Did you count that pronouncement of divorce? He said: Why not?
طَلَّقْتُ امْرَأَتِي وَهْىَ حَائِضٌ فَأَتَى عُمَرُ النَّبِيَّ ﷺ فَأَخْبَرَهُ فَقَالَ مُرْهُ فَلْيُرَاجِعْهَا ثُمَّ إِذَا طَهَرَتْ فَلْيُطَلِّقْهَا قُلْتُ لاِبْنِ عُمَرَ أَفَاحْتَسَبْتَ بِتِلْكَ التَّطْلِيقَةِ قَالَ فَمَهْ