‘Abd Allah bin Umar said that he divorced his wife while she was menstruating during the time of the Apostle of Allaah ﷺ. So ‘Umar bin Al Khattab asked the Apostle of Allaah ﷺ about this matter. The Apostle of Allaah ﷺ said “Order him, he must take her back and keep her back till she is purified, then has another menstrual period and is purified. Thereafter if he desires he may divorce her before having intercourse with her, for that is the period of waiting which Allaah the Glorified has commanded for the divorce of women.” (Using translation from Abū Dāʾūd 2179)
أَنَّهُ طَلَّقَ امْرَأَتَهُ وَهِيَ حَائِضٌ عَلَى عَهْدِ رَسُولِ اللهِ ﷺ فَسَأَلَ عُمَرُ بْنُ الْخَطَّابِ ؓ رَسُولَ اللهِ ﷺ عَنْ ذَلِكَ فَقَالَ رَسُولُ اللهِ ﷺ مُرْهُ فَلْيُرَاجِعْهَا ثُمَّ لِيُمْسِكْهَا حَتَّى تَطْهُرَ ثُمَّ تَحِيضَ ثُمَّ تَطْهُرَ ثُمَّ إِنْ شَاءَ أَمْسَكَ بَعْدَ ذَلِكَ وَإِنْ شَاءَ طَلَّقَ قَبْلَ أَنْ يَمَسَّ فَتِلْكَ الْعِدَّةُ الَّتِي أَمَرَ اللهُ أَنْ يُطَلَّقَ لَهَا النِّسَاءُ