Sahih Bukhari
Virtues and Merits of the Prophet (pbuh) and his Companions
Volume: 004 / Book Number: 056 / Hadith Number: 702
Narrated Abi Mas'ud:
The Prophet said, "From this side from the east, afflictions will appear. Rudeness and lack of mercy are characteristics of the rural bedouins who are busy with their camels and cows (and pay no attention to religion). Such are the tribes of Rabi'a and Mudar."