he divorced his wife when she was menstruating, and 'Umar mentioned that to the Prophet ﷺ. He said: "Tell him to take her back then divorce her when she is pure (not menstruating) or pregnant." (Using translation from Ibn Mājah 2023)
أَنَّهُ طَلَّقَ امْرَأَتَهُ وَهِيَ حَائِضٌ فَذَكَرَ ذَلِكَ عُمَرُ لِلنَّبِيِّ ﷺ فَقَالَ مُرْهُ فَلْيُرَاجِعْهَا ثُمَّ لِيُطَلِّقْهَا طَاهِرًا أَوْ حَامِلًا