Musannaf Ibn Abi Shayba 17:1302

Abu Bakr narrated to us, he said: Affan narrated to us, from Sakin ibn Abd al-Aziz, from al-Hajari, from Abu al-Ahwas, from Abdullah, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "He who is moderate will not become poor."