The explanation means that the trouble happened at home. Metaphor is internal disaster. A small wall used as a door in an ancient palace.

"The Analects of Confucius Ji" said: "Today's reason and seeking common ground are also teachers. People far away are dissatisfied and can't come. " The state is falling apart and can't keep it; I am afraid of inner pain, not in a corner, but in a small wall. "

Confucius told his two students and Ran Qiu that you two should be assistants at Ji's house, but you can't come because you are too far away. People are not angry with you, your political morality can't convince them, and they don't get along. At home, it's on and off. On the surface, it is a whole, and many internal factors are divided. Everyone will collapse sooner or later if they leave Germany. This situation is untenable, because internal disintegration is difficult to protect itself, so we have to develop outward and divert people's attention. This is the same reason. Therefore, Confucius said, because many internal problems can't be solved, you have to use troops and wage war abroad to divert your internal attention. In my opinion, you are dangerous. The biggest worry, pain and sorrow of Ji's family is not in this small border country, but within the small wall and between Ji's own brothers. Soon after Confucius said this, the brothers of Kyrgyzstan really had problems. Therefore, when there is disaster in future generations, we use the phrase "disaster comes from the wall". Literary allusions come from Confucius' words.

The battle for the crown of the prince is also an internal cholera, so it is called Xiao Qiang's disaster, but the word "Xiao Qiang's disaster" does not specifically refer to the civil strife of the prince.