Hadith
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، عَنْ أُمِّ سَلَمَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَنَّ امْرَأَةً كَانَتْ تُهَرَاقُ الدِّمَاءَ عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم فَاسْتَفْتَتْ لَهَا أُمُّ سَلَمَةَ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ " لِتَنْظُرْ عِدَّةَ اللَّيَالِي وَالأَيَّامِ الَّتِي كَانَتْ تَحِيضُهُنَّ مِنَ الشَّهْرِ قَبْلَ أَنْ يُصِيبَهَا الَّذِي أَصَابَهَا فَلْتَتْرُكِ الصَّلاَةَ قَدْرَ ذَلِكَ مِنَ الشَّهْرِ فَإِذَا خَلَّفَتْ ذَلِكَ فَلْتَغْتَسِلْ ثُمَّ لْتَسْتَثْفِرْ بِثَوْبٍ ثُمَّ لْتُصَلِّ فِيهِ " .
Narrated Umm Salamah, Ummul Mu'minin: In the time of the Messenger of Allah (ﷺ) there was a woman who had an issue of blood. So Umm Salamah asked the Messenger of Allah (ﷺ) to give a decision about her. He said: She should consider the number of nights and days during which she used to menstruate each month before she was afflicted with this trouble and abandon prayer during that period each month. When those days and nights are over, she should take a bath, tie a cloth over her private parts and pray
Sahih · Al-Albani
Sunan Abi Dawud 274 ·Book 1, Hadith 274·Also available on sunnah.com·