Musnad Ahmad 435:101

He said: And the Messenger of Allah, may Allah bless him and grant him peace, said: "The people are followers of Quraysh in this matter; their best in the Pre-Islamic Period (Jahiliyyah) are their best in Islam, if they attain understanding (fiqh). By Allah, were it not that Quraysh would become arrogant, I would have informed them of what their best ones have with Allah, the Almighty and Majestic."