- This expression permits little variation, except for heap insult on injury.
This was derived from the fables of Phaedrus in the first century AD. The story was of a bald man who swats at a fly which has just bitten him on the head, but instead hits himself on the head. The fly comments, "You wished to kill me for a touch. What will you do to yourself since you have added insult to injury". The actual wording appears in English from the middle of the 18th century.