expound vs set forth

expound

verb
  • To set out the meaning of; to explain or discuss at length 

  • To make a statement, especially at length. 

set forth

verb
  • To state; describe; give an account of. 

  • To present for consideration; to propose. 

  • To begin a journey or expedition. 

  • To start. 

How often have the words expound and set forth occurred in a corpus of books? (source: Google Ngram Viewer )