It refers to "see no evil, don't listen if you are indecent, don't speak if you are indecent, and don't move if you are indecent".

It probably means don't watch, listen to, say or do anything that is inappropriate. This is to show Confucius' admonition with four young monks of different shapes.

The four young monks are in a crouching posture, and they look naive: the first one covers his ears, the second one covers his cheeks, the third one covers his eyes, and the fourth one covers his mouth. Incisively and vividly shows the cautious, kind and uncontested life character.

The moral of the four little monks originated from The Analects of Confucius. Yan Yuan asked his teacher Confucius what benevolence was. Confucius said, self-denial is benevolence. Yan Yuan asked again, what are the specific requirements. Confucius replied: "see no evil, don't listen to evil, don't say evil, don't move if you are evil." Buddhist meditation and Confucian thought of great harmony are subtly integrated in the thinking of the four young monks.

Etiquette is reason, that is, people's code of conduct and inner requirements. In Confucius' view, when people are alive, they all have desires. Reasonable desires are called justice, while excessive desires are called human desires. Therefore, it is necessary to seek justice from others. In fact, these four sentences require people to keep their inner conscience, do what they know is good, and stop what they know is evil. Don't let nature take its course.

in a modern society ruled by law, courtesy is the legal system and moral norms. The civilized world has solved the problem of survival, and everyone says that they should pursue freedom. Freedom can give full play to nature, but excessive freedom will infringe on the freedom of others and lead to conflicts. This requires legal system and moral norms to restrict and limit people's freedom to ensure that you can be free and others can be free.