The Book of Divorce
18/1. Chapter:
The prohibition of divorcing a menstruating woman without her consent; If a man breaks this rule, it still counts as a divorce, and he should be ordered to take her back
Sahih Muslim
وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا ابْنُ جُرَيْجٍ، أَخْبَرَنِي ابْنُ طَاوُسٍ، عَنْ أَبِيهِ، أَنَّهُ سَمِعَ ابْنَ عُمَرَ، يُسْأَلُ عَنْ رَجُلٍ، طَلَّقَ امْرَأَتَهُ حَائِضًا فَقَالَ أَتَعْرِفُ عَبْدَ اللَّهِ بْنَ عُمَرَ قَالَ نَعَمْ . قَالَ فَإِنَّهُ طَلَّقَ امْرَأَتَهُ حَائِضًا فَذَهَبَ عُمَرُ إِلَى النَّبِيِّ صلى الله عليه وسلم فَأَخْبَرَهُ الْخَبَرَ فَأَمَرَهُ أَنْ يُرَاجِعَهَا قَالَ لَمْ أَسْمَعْهُ يَزِيدُ عَلَى ذَلِكَ لأَبِيهِ.
Ibn Tawus narrated on the authority of his father that Ibn 'Umar (Allah be pleased with them) was asked about the person who divorced his wife in the state of menses, whereupon he said: Do you know 'Abdullah b. Umar? He said: Yes. He said: It was he who divorced his wife jn the state of menses and 'Umar went to Allah's Apostle (ﷺ) and gave him this information. and he commanded him that he should take her back; and he (Abu Tawus) said: I did not hear any addition to this (hadith) from my father.
Reference : Sahih Muslim 1471rIn-book reference : Book 18, Hadith 18USC-MSA web (English) reference : Book 9, Hadith 3488