Mishkat al-Masabih #911

Abu Huraira reported God’s Messenger as saying, “If anyone says ‘Glory be to God’ after every prayer thirty-three times, ‘Praise be to God’ thirty-three times, and ‘God is most great’ thirty-three times, ninety-nine times in all, and says to complete a hundred, ‘There is no god but God alone who has no partner; to Him belongs the kingdom, to Him praise is due, and He is omnipotent,’ his sins will be forgiven, even if they are as abundant as the foam of the sea.” Muslim transmitted it.