Musannaf Ibn Abi Shayba 27:747

Yazid ibn Harun narrated to us, from Ibn Abi Dhi’b, from al-Zuhri, from Talha ibn Abdullah ibn Awf, from Abd al-Rahman ibn al-Azhar, from Jubayr ibn Mut’im, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Indeed, for a Qurayshi is the like of the strength of two men from other than Quraysh." It was said to al-Zuhri: "What did he mean by that?" He said: "In the nobility of opinion."