Musnad Ahmad 5:228

Abdullah narrated to us, Muhammad ibn Sulayman Luwayn narrated to me, Muhammad ibn Jabir narrated to us, from Abd al-Malik ibn Umayr, from Umarah ibn Ruwaybah, from Ali ibn Abi Talib, who said: My ears heard, and my heart retained, from the Messenger of Allah (may Allah bless him and grant him peace): "The people are followers of Quraysh; their righteous ones are followers of their righteous ones, and their wicked ones are followers of their wicked ones."