Musannaf Ibn Abi Shayba 27:746

Ya'la ibn 'Ubayd narrated to us, from Muhammad ibn 'Amr, from Abu Salamah, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The people are followers of Quraysh in this matter; their best are followers of their best, and their worst are followers of their worst."