Musnad Ahmad 27:1579

Hashim narrated to us, Ishaq bin Sa'id bin 'Amr bin Sa'id bin al-'As narrated to us, from his father Sa'id bin 'Amr, from Ibn 'Umar, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "The upper hand is better than the lower hand." Ibn 'Umar said: "So I did not ask 'Umar, nor anyone else among the people [about it]."