Musnad Ahmad 470:4

Abu Ahmad narrated to us, he said: Sufyan narrated to us, from Abu Ishaq, from Abu al-Ahwas, from his father Malik, who said: I said: "O Messenger of Allah, a man passes by me, and he does not host me nor does he show me hospitality, then he passes by me [again], should I requite him?" He said: "No, rather show him hospitality." He said: Then he saw me in tattered clothes. He said: "Do you have any wealth?" I said: "Allah the Almighty has given me of every kind of wealth, of camels and sheep." He said: "Then let the effect of Allah’s blessing upon you be seen."