To strike one’s fist on a lion, and to grasp the sharp edge of a sword with the hand, is not the part of an intelligent man.
Do not fight or try thy strength with a furious man.
Hide thy hands in thy arm-pits to avoid his finger-nails.
Saadi Shirazi
http://www.poemhunter.com/poem/ch-08-on-rules-for-conduct-in-life-maxim-29/
