Musnad Ahmad 26:719

I read to my father: Abu Ubaydah al-Haddad narrated to us, he said: Sukayn bin Abd al-Aziz al-Abdi narrated to us, Ibrahim al-Hajari narrated to us, from Abu al-Ahwas, from Abdullah bin Mas’ud, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "He who is moderate will not become poor."