Musnad Ahmad 31:384

Yunus ibn Muhammad narrated to us, Layth narrated to us, from Yazid ibn Abi Habib, from Abu al-Khayr, from Abu al-Khattab, from Abu Sa’id al-Khudri, that he said: The Messenger of Allah (may Allah bless him and grant him peace), in the year of Tabuk, addressed the people while his back was leaning against a date palm tree. He said: "Shall I not inform you of the best of people and the worst of people? Indeed, among the best of people is a man who works in the way of Allah upon the back of his horse—or upon the back of his camel, or on his feet—until death comes to him. And indeed, among the worst of people is a wicked, audacious man who reads the Book of Allah, yet does not refrain from anything of it."