Where does the expression "Eat your heart...

This expression first surfaced in the late 1500’s and means “look at me and be envious” or “suffer vexation over my situation” from the Yiddish phrase “Es dir cys s’harts” or “eat out your heart”. It acquired a more widespread usage as a humorous phrase in the 1950’s show business world and came to mean something on the order of “Nyah, nyah, I can do as well as you can.”