Musnad Ahmad 30:955

Muhammad ibn Bakr al-Bursani narrated to us, Ja'far—meaning Ibn Burqan—narrated to us, he said: I heard Yazid ibn al-Asamm, from Abu Hurairah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "I do not fear poverty for you, but I fear competition for worldly increase for you. And I do not fear error for you, but I fear intentionality for you."