If you have yourself, you will ask others. If you don't have yourself, you are not others. Hidden things are unforgivable, but they can be used to describe people, but nothing is left.

This sentence comes from Confucius, which roughly means: what you do first, then ask others to do it, and what you should not do first, then ask others not to do it. No one can convince others but measure people's hearts by himself.