explain vs gild the lily

explain

verb
  • To make something plain or intelligible. 

  • To make plain, manifest, or intelligible; to clear of obscurity; to illustrate the meaning of. 

  • To give a valid excuse for past behavior. 

gild the lily

verb
  • To embellish or improve something unnecessarily. 

  • To add superfluous attributes to something. 

How often have the words explain and gild the lily occurred in a corpus of books? (source: Google Ngram Viewer )