Musnad Ahmad 937:89

'Affan narrated to us, Abu 'Awanah narrated to us, from 'Asim, from al-Ma'rur ibn Suwayd, from Abu Dharr, who said: I heard the Messenger of Allah (peace and blessings of Allah be upon him), the truthful, the believed, saying: "Allah, the Almighty and Majestic, said: 'A good deed is ten [times its reward] or more, and a bad deed is one, or I forgive it. Whoever meets Me without associating anything with Me, even if he comes with the earth full of sins, I will grant him the like thereof in forgiveness.'"