gods willing vs knock on wood

gods willing

intj
  • Used to express hope that gods are willing (to grant one's desires). 

knock on wood

intj
  • Hopefully; a self-directive to undertake the customary action to ward off bad luck. 

verb
  • To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement. 

How often have the words gods willing and knock on wood occurred in a corpus of books? (source: Google Ngram Viewer )