Sahih Muslim Book 020, Hadith Number 4475.
Chapter : The people are subservient to the Quraish and the Caliphate is the right of the Quraish.
It has been narrated on the authority of Jabir b. 'Abdullah that the Messenger of Allah (may peace be upon him) said: People are the followers of Quraish in good as well as evil (i.e. in the customs of Islamic as well as pre-Islamic times).