حَدَّثَنَا مُحَمَّدُ بْنُ عُبَيْدٍ حَدَّثَنَا عُبَيْدُ اللَّهِ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ قَالَ طَلَّقْتُ امْرَأَتِي عَلَى عَهْدِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهِيَ حَائِضٌ فَذَكَرَ ذَلِكَ عُمَرُ لِرَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ مُرْهُ فَلْيُرَاجِعْهَا حَتَّى تَطْهُرَ ثُمَّ تَحِيضَ أُخْرَى فَإِذَا طَهُرَتْ يُطَلِّقُهَا إِنْ شَاءَ قَبْلَ أَنْ يُجَامِعَهَا أَوْ يُمْسِكَهَا فَإِنَّهَا الْعِدَّةُ الَّتِي أَمَرَ اللَّهُ أَنْ تُطَلَّقَ لَهَا النِّسَاءُ
مسند امام احمد بن حنبل · Hadith 5792
It was narrated that Ibn 'Umar said: I divorced my wife at the time of the Messenger of Allah (PBUH) when she was menstruating. 'Umar told the Messenger of Allah (PBUH) about that and he said: "Tell him to take her back until she has become pure, then has another period, then when she has become pure again, he may divorce her, if he wishes, before he has intercourse with her or he may keep her. That is the 'iddah {prescribed periods) at which Allah has enjoined the divorce of women."
Sanad
حَدَّثَنَا مُحَمَّدُ بْنُ عُبَيْدٍ حَدَّثَنَا عُبَيْدُ اللَّهِ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ