Sahih al-Bukhari 816
صحيح البخاري#816SahihNarrated Ibn `Abbas:The Prophet (ﷺ) said, "I have been ordered to prostrate on seven (bones) and not to tuck up the hair or garment
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: 10:211