Yahya related to me from Malik from Hisham ibn Urwa from his father from Fatima bint al-Mundhir ibn az-Zubayr that Asma bint Abu Bakr as-Siddiq said, "A woman questioned the Messenger of Allah ﷺ saying, 'If menstrual blood gets onto our clothes how do you think we should deal with it?' The Messenger of Allah ﷺ said, 'If menstrual blood gets onto your clothes you should wash them, and sprinkle them with water before you pray in them.' "
أَنَّهَا قَالَتْ سَأَلَتِ امْرَأَةٌ رَسُولَ اللَّهِ ﷺ فَقَالَتْ أَرَأَيْتَ إِحْدَانَا إِذَا أَصَابَ ثَوْبَهَا الدَّمُ مِنَ الْحَيْضَةِ كَيْفَ تَصْنَعُ فِيهِ فَقَالَ رَسُولُ اللَّهِ ﷺ إِذَا أَصَابَ ثَوْبَ إِحْدَاكُنَّ الدَّمُ مِنَ الْحَيْضَةِ فَلْتَقْرُصْهُ ثُمَّ لِتَنْضَحْهُ بِالْمَاءِ ثُمَّ لِتُصَلِّي فِيهِ