Sahih Muslim 753
صحيح مسلم#753SahihA'isha reported:Fatimah b. Abu Hubaish came to the Apostle (ﷺ) and said: I am a woman whose blood keeps flowing (even after the menstruation period). I am never purified; should I, therefore, abandon prayer? He (the Holy Prophet) said: Not at all, for that is only a vein, and is not a menstruation, so when menstruation comes, abandon prayer, and when it ends wash the blood from yourself and then pray
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 3:75