hymn vs pat on the back

hymn

verb

  • To praise or extol in hymns. 

  • To sing a hymn. 

noun

  • A song of praise or worship, especially a religious one. 

pat on the back

verb

  • To praise or congratulate. 

noun

  • Praise, congratulations. 

How often have the words hymn and pat on the back occurred in a corpus of books? (source: Google Ngram Viewer )