Sahih Muslim Book - 18, Hadith - 3656

وَحَدَّثَنِى زُهَيْرُ بْنُ حَرْبٍ حَدَّثَنَا إِسْمَاعِيلُ عَنْ أَيُّوبَ عَنْ نَافِعٍ أَنَّ ابْنَ عُمَرَ طَلَّقَ امْرَأَتَهُ وَهْىَ حَائِضٌ فَسَأَلَ عُمَرُ النَّبِىَّ -صلى الله عليه وسلم- فَأَمَرَهُ أَنْ يَرْجِعَهَا ثُمَّ يُمْهِلَهَا حَتَّى تَحِيضَ حَيْضَةً أُخْرَى ثُمَّ يُمْهِلَهَا حَتَّى تَطْهُرَ ثُمَّ يُطَلِّقَهَا قَبْلَ أَنْ يَمَسَّهَا فَتِلْكَ الْعِدَّةُ الَّتِى أَمَرَ اللَّهُ أَنْ يُطَلَّقَ لَهَا النِّسَاءُ. قَالَ فَكَانَ ابْنُ عُمَرَ إِذَا سُئِلَ عَنِ الرَّجُلِ يُطَلِّقُ امْرَأَتَهُ وَهْىَ حَائِضٌ يَقُولُ أَمَّا أَنْتَ طَلَّقْتَهَا وَاحِدَةً أَوِ اثْنَتَيْنِ. إِنَّ رَسُولَ اللَّهِ -صلى الله عليه وسلم- أَمَرَهُ أَنْ يَرْجِعَهَا ثُمَّ يُمْهِلَهَا حَتَّى تَحِيضَ حَيْضَةً أُخْرَى ثُمَّ يُمْهِلَهَا حَتَّى تَطْهُرَ ثُمَّ يُطَلِّقَهَا قَبْلَ أَنْ يَمَسَّهَا وَأَمَّا أَنْتَ طَلَّقْتَهَا ثَلاَثًا فَقَدْ عَصَيْتَ رَبَّكَ فِيمَا أَمَرَكَ بِهِ مِنْ طَلاَقِ امْرَأَتِكَ. وَبَانَتْ مِنْكَ.

It was narrated from Nafi' that Ibn 'Umar divorced his wife while she was menstruating, and 'Umar asked the Prophet (s.a.w) about that. He (s.a.w) ordered him to take her back, then wait until she had menstruated again, then wait until she became pure, then he could divorce her before having intercourse with her. That is the 'Iddah (prescribed periods) for which Allah has enjoined the divorce of women. He said: "When Ibn 'Umar was asked about a man who divorces his wife while she is menstruating, he would say: 'If you have divorced her once or twice, the Messenger of Allah (s.a.w) told him to take her back, then wait until she menstruated again, then wait until she became pure, then divorce her before having intercourse with her. If you divorced her three times, then you have disobeyed your Lord with regard to the manner in which He commanded you to divorce your wife, and the divorce is irrevocable."'