كتاب الطلاق
Read the English translation first, with the original Arabic directly underneath.
‘Abd Allah bin Umar said that he divorced his wife while she was menstruating during the time of the Messenger of Allaah(ﷺ). So ‘Umar bin Al Khattab asked the Messenger of Allaah(ﷺ) about this matter. The Messenger of Allaah(ﷺ) said “Order him, he must take her back and keep her back till she is purified, then has another menstrual period and is purified. Thereafter if he desires he may divorce her before having intercourse with her, for that is the period of waiting which Allaah the Glorified has commanded for the divorce of women.”
مُرْهُ فَلْيُرَاجِعْهَا ثُمَّ لْيُمْسِكْهَا حَتَّى تَطْهُرَ ثُمَّ تَحِيضَ ثُمَّ تَطْهُرَ ثُمَّ إِنْ شَاءَ أَمْسَكَ بَعْدَ ذَلِكَ وَإِنْ شَاءَ طَلَّقَ قَبْلَ أَنْ يَمَسَّ فَتِلْكَ الْعِدَّةُ الَّتِي أَمَرَ اللَّهُ سُبْحَانَهُ أَنْ تُطَلَّقَ لَهَا النِّسَاءُ