commend vs sing the praises of

commend

verb
  • To praise or acclaim. 

  • To recommend. 

  • To entrust or commit to the care of someone else. 

  • To mention by way of courtesy, implying remembrance and goodwill. 

  • To congratulate or reward. 

sing the praises of

verb
  • to commend someone's attributes to others 

How often have the words commend and sing the praises of occurred in a corpus of books? (source: Google Ngram Viewer )