Musnad Ahmad 937:275

Hashim narrated to us, Shaiban narrated to us, from Asim, from al-Ma'rur ibn Suwayd, from Abu Dharr, who said: The Truthful, the Believed narrated to me—raising the hadith—he said: "A good deed is ten [times its reward] or more, and a bad deed is one, or I forgive it. And whoever meets Me without associating anything with Me, even if he comes with the earth full of sins, I will grant him the equivalent of it in forgiveness."