This sentence is so popular because of Stephen Chow's film "Nine-grade Sesame Officer". At that time, in the face of powerful people and bullies, Stephen Chow shouted: "Close the door and let the dog go!" Then the gate of the yamen slammed shut, and his guards and touts jumped out like dogs to bite! That scene ... 100 million people laughed!

This scene is: close the door, let the other side have no way to escape, and then let the dog attack the other side. It is a vicious means to make the other side desperate.

Since then, many people have made fun of this sentence. When they want to clean up each other or threaten to clean up each other, they joked, "Close the door! Let the dog go! "