Sahih al-Bukhari 4387
صحيح البخاري#4387SahihNarrated Abu Masud:The Prophet (ﷺ) beckoned with his hand towards Yemen and said, "Belief is there." The harshness and mercilessness are the qualities of those farmers etc, who are busy with their camels and pay no attention to the religion (is towards the east) from where the side of the head of Satan will appear; those are the tribes of Rabi`a and Mudar
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: 64:410