Sahih al-Bukhari 308
صحيح البخاري#308SahihNarrated `Aisha:Whenever anyone of us got her menses, she, on becoming clean, used to take hold of the blood spot and rub the blood off her garment, and pour water over it and wash that portion thoroughly and sprinkle water over the rest of the garment. After that she would pray in (with) it
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: 6:13