"I divorced my wife when she was menstruating. 'Umar mentioned that to the Messenger of Allah and he said: 'Tell him to take her back until she becomes pure (i.e., her period ends), then she has her period (again), then she becomes pure (again), then if he wishes he may divorce her before having sexual relations with her, and if he wishes he may keep her. This is the waiting period that Allah has enjoined.'" (Using translation from Ibn Mājah 2019)
طَلَّقْتُ امْرَأَتِي عَلَى عَهْدِ رَسُولِ اللهِ ﷺ وَهِيَ حَائِضٌ فَذَكَرَ ذَلِكَ عُمَرُ لِرَسُولِ اللهِ ﷺ فَقَالَ مُرْهُ فَلْيُرَاجِعْهَا حَتَّى تَطْهُرَ ثُمَّ تَحِيضَ أُخْرَى فَإِذَا طَهُرَتْ يُطَلِّقُهَا إِنْ شَاءَ قَبْلَ أَنْ يُجَامِعَهَا أَوْ يُمْسِكَهَا فَإِنَّهَا الْعِدَّةُ الَّتِي أَمَرَ اللهُ أَنْتُطَلَّقَ لَهَا النِّسَاءُ