"The mouth can speak, the body can do it" comes from "Xunzi's Outline", which is a fragment of a chapter. The original text is:

"If the mouth can speak, the body can do it, it is a national treasure. If the mouth cannot speak, but the body can do it, it is a weapon of the country. If the mouth can speak, but the body cannot do it, it is a national weapon. . What is said is good but the body is evil. Those who govern the country respect its treasures, love its weapons, and let them be used to get rid of the monsters."

The translation of this chapter is:

People who can talk about etiquette and justice themselves and practice etiquette and justice themselves are the treasures of the country. People who cannot talk about etiquette and righteousness but can practice etiquette and righteousness themselves are instruments of the state. A person who can talk about etiquette and righteousness but cannot practice etiquette and righteousness himself can only be a tool of the state. People who talk well but do bad things themselves are simply the monsters of the country. Those who govern the country respect the country's treasures, care for the country's utensils, use the country's tools, and eradicate the country's evildoers.

This reflects the Xunzi school’s concept of good and evil.

The concepts of good and evil are the most basic values ??of society. Xunzi's school of thought believes that it may be easy for people to talk about good and evil, and that the key to the problem is action. Through the hierarchical distinction between national treasures, national utensils, national uses and national monsters, it tells people that the country should "respect its treasures, love its utensils, allow them to be used, and get rid of their monsters." No matter how small the good deed is, we should do it with all our heart, and no matter how small the evil deed is, we will never participate in it. Among them, Xunzi believes that the "national demon" must be eliminated, which reflects his deep sorrow for those who say good things and do evil.

Doing good and eliminating evil, and integrating knowledge and action have been fine traditions of the Chinese nation since ancient times. In the Chinese cultural tradition, the mutual promotion of theoretical thinking and practical participation has always been praised and respected, and it is also the social morality that we should still follow today.