Musnad Ahmad 28:495

Abdullah ibn Bakr, meaning al-Sahmi, narrated to us, Hatim narrated to us, from Abu Balj, from Amr ibn Maymun, that he informed him that he heard Abdullah ibn Amr narrating from the Messenger of Allah, peace and blessings of Allah be upon him, who said: "There is no man on the earth who says: 'La ilaha illa Allah' (There is no god but Allah), 'wa Allahu Akbar' (and Allah is the Greatest), 'wa Subhan Allah' (and glory be to Allah), 'wa al-hamdu lillah' (and praise be to Allah), 'wa la hawla wa la quwwata illa billah' (and there is no power and no strength except by Allah), but that his sins are expiated for him, even if they were like the foam of the sea."