heap on vs pass off

heap on

verb
  • To give someone a lot of something (advice, praise, insults, etc.), especially more so than they can handle or is appropriate 

pass off

verb
  • To give something (to someone). 

  • To abate, to cease gradually. 

  • To happen. 

How often have the words heap on and pass off occurred in a corpus of books? (source: Google Ngram Viewer )