Sahih Muslim 1220
صحيح مسلم#1220SahihMu'aiqib said:They asked the Apostle (ﷺ) about the removal of (pebbles) in prayer, whereupon he said: If you do it, do it only 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 Muslim is accepted as Sahih (authentic) by the established status of the book.