Sahih al-Bukhari 7240
صحيح البخاري#7240SahihNarrated Abu Huraira:Allah's Messenger (ﷺ) said, "Were I not afraid that it would be hard on my followers, I would order them to use the siwak (as obligatory, for cleaning the teeth)
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: 94:15