Sahih al-Bukhari 7070
صحيح البخاري#7070SahihNarrated `Abdullah bin `Umar:Allah's Messenger (ﷺ) said, "Whoever takes up arms against us, is not from us
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: 92:21