Musnad Ahmad 769:40

Al-Hakam ibn Musa narrated to us—Abdullah Abu Abd al-Rahman said: And I heard it myself from al-Hakam—he said: Ibn 'Ayyash narrated to us, from Musa ibn 'Uqbah, from Abu al-Nadr, from 'Ubayd Allah ibn Ma'mar, from Abdullah ibn Abi Awfa, who said: "The Prophet, peace and blessings of Allah be upon him, used to like to set out toward his enemy when the sun had passed its zenith."