Sahih Muslim 688
صحيح مسلم#688SahihAl-Aswad narrated it from 'A'isha that she observed:I used to wash the head of the Messenger of Allah (ﷺ), while I was in a state of menstruation
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: 3:10