Sahih Muslim Book 20, Hadith Number 4474.

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 Hammam b. Munabbih who said: This is one of the traditions narrated by Abu Huraira from the Messenger of Allah (may peace be upon him) who said: People are subservient to the Quraish: the Muslims among them being subservient to the Muslims among them, and the disbelievers among them being subservient to the disbelievers among them.