If you pronounced one divorce or two, Messenger of Allah ﷺ had commanded him to take her back, and then allow her respite until she enters the period of the second menses, and then allow her respite until she is purified, and then divorce her (finally) before touching her (having a sexual intercourse with her) ; and if you have pronounced (three divorces at one and the same time) you have in fact disobeyed your Lord with regard to what He commanded you about divorcing your wife. But she is however (finally separated from you). (Using translation from Muslim 1471e)
أَنَّ ابْنَ عُمَرَ طَلَّقَ امْرَأَتَهُ وَهِيَ حَائِضٌ فَسَأَلَ عُمَرُ النَّبِيَّ ﷺ فَأَمَرَهُ أَنْ يُرَاجِعَهَا ثُمَّ يُمْهِلَهَا حَتَّى تَحِيضَ حَيْضَةً أُخْرَى ثُمَّ يُمْهِلَهَا حَتَّى تَطْهُرَ ثُمَّ يُطَلِّقَهَا قَبْلَ أَنْ يَمَسَّهَا فَتِلْكَ الْعِدَّةُ الَّتِي أَمَرَ اللهُ أَنْ تُطَلَّقَ لَهَا النِّسَاءُ وَكَانَ ابْنُ عُمَرَ إِذَا سُئِلَ عَنِ الرَّجُلِ يُطَلِّقُ امْرَأَتَهُ وَهِيَ حَائِضٌ؟ يَقُولُ إِمَّا أَنْتَ طَلَّقْتَهَا وَاحِدَةً أَوِ اثْنَتَيْنِ فَإِنَّ رَسُولَ اللهِ ﷺ أَمَرَهُ أَنْ يُرَاجِعَهَا ثُمَّ يُمْهِلَهَا حَتَّى تَحِيضَ حَيْضَةً أُخْرَى ثُمَّ يُمْهِلَهَا حَتَّى تَطْهُرَ ثُمَّ يُطَلِّقَهَا إِنْ لَمْ يُرِدْ إِمْسَاكَهَا وَإِمَّا أَنْتَ طَلَّقْتَهَا ثَلَاثًا فَقَدْ عَصَيْتَ اللهَ تَعَالَى فِيمَا أَمَرَكَ بِهِ مِنْ طَلَاقِ امْرَأَتِكَ وَبَانَتْ مِنْكَ وَبِنْتَ مِنْهَا