Musannaf Ibn Abi Shayba 27:848

Yazid ibn Harun narrated to us, he said: Al-Awwam informed us, he said: Mansur narrated to me, from Rib'i ibn Hirash, from Hudhayfah, he said: "Draw near, O assembly of Mudar, for indeed among you is the master of the children of Adam, and among you are those who precede like the precedence of horses."