Musnad Ahmad 27:1227

Abu al-Nadr narrated to us, Asim ibn Muhammad ibn Zayd ibn Abdullah ibn Umar ibn al-Khattab narrated to us, from his father, from Abdullah ibn Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "This matter shall remain in Quraysh as long as two people remain among the people."