oath vs profession

oath

noun
  • 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. 

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

  • A curse, a curse word. 

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

profession

noun
  • A promise or vow made on entering a religious order. 

  • The practitioners of such an occupation collectively. 

  • The declaration of belief in the principles of a religion; hence, one's faith or religion. 

  • Any declaration of belief, faith or one's opinion, whether genuine or (as now often implied) pretended. 

  • An occupation, trade, craft, or activity in which one has a professed expertise in a particular area; a job, especially one requiring a high level of skill or training. 

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