Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 671
Narrated Abu Huraira:
The Prophet said, "The people of Yemen have come to you and they are more gentle and soft-hearted. Belief is Yemenite and Wisdom is Yemenite, while pride and haughtiness are the qualities of the owners of camels (i.e. bedouins). Calmness and solemnity are the characters of the owners of sheep."