Sahih al-Bukhari 6104
صحيح البخاري#6104SahihNarrated 'Abdullah bin 'Umar: Allah's Messenger (ﷺ) said, 'If anyone says to his brother, 'O misbeliever! Then surely, one of them such
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: 78:131