Sahih al-Bukhari 3657
صحيح البخاري#3657SahihNarrated Aiyub:The Prophet (ﷺ) said, "If I were to take a Khalil, I would have taken him (i.e. Abu Bakr) as a Khalil, but the Islamic brotherhood is better
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: 62:9