Sahih al-Bukhari 161
صحيح البخاري#161SahihNarrated Abu Huraira:The Prophet (ﷺ) said, "Whoever performs ablution should clean his nose with water by putting the water in it and then blowing it out, and whoever cleans his private parts with stones should do it with odd number of stones
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: 4:27