Sahih al-Bukhari 890
صحيح البخاري#890SahihNarrated `Aisha:`Abdur-Rahman bin Abi Bakr came holding a Siwak with which he was cleaning his teeth. Allah's Apostle looked at him. I requested `Abdur-Rahman to give the Siwak to me and after he gave it to me I divided it, chewed it and gave it to Allah's Messenger (ﷺ). Then he cleaned his teeth with it and (at that time) he was resting against my chest
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: 11:15