Musnad Abu Ya'la al-Mawsili 246:10

Zuhayr narrated to us, Yazid narrated to us, Ibn Abi Dhi’b narrated to us, from al-Zuhri, from Talhah ibn ‘Abd Allah ibn ‘Awf, from ‘Abd al-Rahman ibn Azhar, from Jubayr ibn Mut’im, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Verily, for the Qurashi is the like of the strength of two men from other than Quraysh." It was said to al-Zuhri: "What is meant by that?" He said: "The nobility of opinion."