cross one's fingers vs pray

cross one's fingers

verb
  • when wishing for luck, or 

  • when telling a lie (and attempting to escape the moral and other consequence of that lie). 

  • To put the middle finger across the index finger, especially 

pray

verb
  • To wish or hope strongly for a particular outcome. 

  • To humbly beg a person for aid or their time. 

  • To direct words, thoughts, or one's attention to God or any higher being, for the sake of adoration, thanks, petition for help, etc. 

adv
  • Please; used to make a polite request 

How often have the words cross one's fingers and pray occurred in a corpus of books? (source: Google Ngram Viewer )