What can an old prostitute do but vow to become chaste, and an policeman not to commit oppression upon men?

A youth who sits in a corner is a hero in the path of God
Because an old man is unable to rise from his corner.
A youth must be strong minded to abstain from lust,
Because even the sexual tool of an old man, of sluggish desire, rises not.

Saadi Shirazi

http://www.poemhunter.com/poem/ch-08-on-rules-for-conduct-in-life-maxim-80/