assertion vs oath

assertion

noun
  • Something which is asserted; a declaration; a statement asserted. 

  • A statement in a program asserting a condition expected to be true at a particular point, used in debugging. 

  • A statement or declaration which lacks support or evidence. 

  • The act of asserting; positive declaration or averment. 

  • Maintenance; vindication 

oath

noun
  • A statement or promise which is strengthened (affirmed) by such a pledge. 

  • A light, irreverent or insulting appeal to a deity or other entity. 

  • A curse, a curse word. 

  • A solemn pledge or promise that invokes a deity, a ruler, or another entity (not necessarily present) to attest the truth of a statement or sincerity of one's desire to fulfill a contract or promise. 

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