Sahih al-Bukhari 331
صحيح البخاري#331SahihNarrated `Aisha:The Prophet (ﷺ) said to me, "Give up the prayer when your menses begin and when it has finished, wash the blood off your body (take a bath) and start praying
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 6:35