bespeak vs let go

bespeak

verb
  • To speak up or out; exclaim; speak. 

  • To betoken; show; indicate; foretell; suggest; allude to. 

  • To speak about; tell of; relate; discuss. 

  • To speak for beforehand; engage in advance; make arrangements for; order or reserve in advance. 

  • To stipulate, solicit, ask for, or request, as in a favour. 

let go

verb
  • Used other than figuratively or idiomatically: see let, go. 

  • To dismiss from employment. 

  • To release from one's grasp; to go from a state of holding on to a state of no longer holding on. 

  • To ignore (a comment, etc.). 

  • To emotionally disengage or to distract oneself from a situation. 

  • To fail to maintain a standard of appearance, behavior, or performance. 

  • To gain weight 

How often have the words bespeak and let go occurred in a corpus of books? (source: Google Ngram Viewer )