(Imām Bukhārī narrates): Abdullah bin Yusuf narrated to us, he said: Imam Malik informed us, from Hisham bin Urwah, from his father, from Hazrat Aisha (may Allāh be pleased with her), she says that

Hazrat Fatimah bint Hubaish (may Allāh be pleased with her) said to the Messenger of Allāh ﷺ: O Messenger of Allāh! Indeed I do not become pure; should I leave prayer? Then the Messenger of Allāh ﷺ said: This is only (the blood) of a vein, and this is not menstruation; so when menstruation comes, leave prayer, and when the amount of menstruation has passed, wash the blood from your body and pray.