Musnad Abu Ya'la al-Mawsili 160:44

Muhammad ibn al-Muthanna narrated to us, Abd al-Wahhab narrated to us, Awf narrated to us, from Khilas, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, the people are followers of Quraysh; their disbelievers are followers of their disbelievers, and their Muslims are followers of their Muslims."