Sahih al-Bukhari 3656
صحيح البخاري#3656SahihNarrated Ibn `Abbas:The Prophet (ﷺ) said, "If I were to take a Khalil, I would have taken Abu Bakr, but he is my brother and my companion (in Islam)
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: 62:8