Origin of salt of the earth
"salt of the earth." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/salt-of-the-earth>.
salt of the earth. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/salt-of-the-earth
From Old English a calque translation of verse from New Testament Matthew V:13