Sahih al-Bukhari 5303
صحيح البخاري#5303SahihNarrated Abu Masud:The Prophet (ﷺ) pointed with his hand towards Yemen and said twice, "Faith is there," and then pointed towards the East, and said, "Verily, sternness and mercilessness are the qualities of those who are busy with their camels and pay no attention to their religion, where the two sides of the head of Satan will appear," namely, the tribes of Rabl'a and Muqar
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: 68:52