Musnad Abu Ya'la al-Mawsili 5:16

Abu Khaythama narrated to us, Muhammad ibn Kunasa narrated to us, Hisham ibn Urwa narrated to us, from Uthman ibn Urwa, from his father, from al-Zubayr, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Change the gray hair, and do not resemble the Jews."