Musnad Abu Ya'la al-Mawsili 160:155

Ahmad ibn Imran al-Akhnasi narrated to us, Muhammad ibn Fudayl narrated to us, Abdullah ibn Sa'id narrated to us, from his grandfather, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "You will never be able to encompass the people with your wealth, but they can be encompassed by you through a cheerful face."