Ibn ʿUmar divorced his wife while she was having her menses. ʿUmar asked the Prophet ﷺ who said, "Order him (your son) to take her back, and then divorced her before her period of the 'Iddah has elapsed." I asked Ibn ʿUmar, "Will that divorce (during the menses) be counted?" He replied, "If somebody behaves foolishly (will his foolishness be an excuse for his misbehavior)?"
طَلَّقَ ابْنُ عُمَرَ امْرَأَتَهُ وَهْىَ حَائِضٌ فَسَأَلَ عُمَرُ النَّبِيَّ ﷺ فَأَمَرَهُ أَنْ يُرَاجِعَهَا ثُمَّ يُطَلِّقَ مِنْ قُبُلِ عِدَّتِهَا قُلْتُ فَتَعْتَدُّ بِتِلْكَ التَّطْلِيقَةِ قَالَ أَرَأَيْتَ إِنْ عَجَزَ وَاسْتَحْمَقَ