It was narrated from 'Aishah that Fatimah bint Abi Hubaish suffered from Istihadah. The Messenger of Allah (ﷺ) said to her:"Menstrual blood is blood that is black and recognizable, so if it is like that, then stop praying, and if it is otherwise, then perform Wudu' and pray." Abu 'Abdur-Rahman said: Others reported this Hadith, and none of them mentioned what Ibn 'Adi mentioned, and Allah knows best

English translation · Sunan an-Nasa'i