Musannaf Ibn Abi Shayba 21:676

Waki’ narrated to us, he said: Al-A’mash narrated to us, from Jami’ ibn Shaddad, from Mughith ibn Sumayy, who said: There was a man among those who were before you who used to commit sins. Then he remembered one day and said, "O Allah, Your forgiveness, Your forgiveness." So He forgave him.