(15) باب خَيْرُ مَالِ الْمُسْلِمِ غَنَمٌ يَتْبَعُ بِهَا شَعَفَ الْجِبَالِ
Narrated `Uqba bin `Umar and Abu Mas`ud:
Allah's Messenger (ﷺ) pointed with his hand towards Yemen and said, "True Belief is Yemenite yonder (i.e. the Yemenite, had True Belief and embraced Islam readily), but sternness and mercilessness are the qualities of those who are busy with their camels and pay no attention to the Religion where the two sides of the head of Satan will appear. Such qualities belong to the tribe of Rabi`a and Mudar."
Reference: Sahih al-Bukhari 3302
In-book reference: Book 59, Hadith 110
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 54, Hadith 521