Sahih Muslim 1098
صحيح مسلم#1098SahihIbn Abbas reported that the Messenger of Allah (ﷺ) said:I have been commanded to prostrate myself on seven bones:" forehead," and then pointed with his hand towards his nose, hands, feet, and the extremities of the feet; and we were forbidden to fold back clothing and hair
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: 4:260