Musannaf Ibn Abi Shayba 27:743

Abdullah ibn Idris narrated to us, he said: Hashim ibn Hashim narrated to us, from Abu Ja'far, he said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Do not precede Quraysh, lest you go astray, and do not lag behind them, lest you go astray. The best of Quraysh are the best of people, and the worst of Quraysh are the worst of people. By the One in whose hand is the soul of Muhammad, were it not that Quraysh would become arrogant, I would have informed them of what the best among them have with Allah, or what they have with Allah."