goad vs light a fire under

goad

verb
  • To encourage or stimulate. 

  • To incite or provoke. 

  • To prod with a goad. 

noun
  • That which goads or incites; a stimulus. 

  • A long, pointed stick used to prod animals. 

light a fire under

verb
  • To motivate or encourage (someone) to start sooner or move faster. 

How often have the words goad and light a fire under occurred in a corpus of books? (source: Google Ngram Viewer )