Musnad Ahmad 30:3827

Kathir narrated to us, Ja'far narrated to us, he said: I heard Yazid ibn al-Asamm saying: Abu Hurayrah said—a hadith I do not think but that he attributed it to the Prophet, may Allah bless him and grant him peace—he said: "Wealth is not from the abundance of worldly goods, but wealth is the richness of the soul. By Allah, I do not fear poverty for you, but I fear for you the accumulation of wealth. And I do not fear error for you, but I fear for you intentional wrongdoing."