profess vs solemnly promise

profess

verb
  • To administer the vows of a religious order to (someone); to admit to a religious order. 

  • To declare one's adherence to (a religion, deity, principle etc.). 

  • To work as a professor of; to teach. 

  • To declare oneself (to be something). 

  • To make a claim (to be something); to lay claim to (a given quality, feeling etc.), often with connotations of insincerity. 

  • To declare; to assert, affirm. 

solemnly promise

How often have the words profess and solemnly promise occurred in a corpus of books? (source: Google Ngram Viewer )