Mishkat al-Masabih 910

Ka'b b. ‘Ujra reported God’s Messenger as saying, “There are certain remembrances the repeaters (or, performers)* of which after every prescribed prayer will never be caused disappointment: ‘Glory be to God’ thirty-three times, ‘Praise be to God’ thirty-three times, and ‘God is most great’ thirty-four times.” * The transmitter gives this alternative, thus showing that he is not sure which word was used. Muslim transmitted it.