Sahih al-Bukhari 1207
صحيح البخاري#1207SahihNarrated Mu'aiqib:The Prophet (ﷺ) talked about a man leveling the earth on prostrating, and said, "If you have to do so, then do it once
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: 21:11