Musnad Ahmad 30:3448

Yazid narrated to us, Muhammad informed us, from Abu al-Zinad, from al-A'raj, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The head of disbelief is towards the east. Pride and arrogance are in the people of horses and camels, among the loud-voiced people of the wool-dwellers. And tranquility is in the people of sheep."