Musnad Ahmad 32:1106

Zayd ibn al-Hubab narrated to us, he said: Ali ibn Mas'adah al-Bahili informed me, from Qatadah, from Anas, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Every son of Adam is a sinner, and the best of the sinners are those who repent. And if the son of Adam had two valleys of wealth, he would seek a third for them, and nothing fills the belly of the son of Adam except dust."