This sentence comes from Zhuangzi's Death of Chaos: the emperor is Shu, the emperor of Beihai is negligence, and the emperor of the Central Plains is chaos. Shu and suddenly meet in a chaotic place, and chaos is good for them. Shu He suddenly asked for the virtue of chaos, saying, "Everyone has seven senses of sight, hearing, food and rest, which is unique. Try to chisel it. " If you dig a hole during the day, you will die in the chaos on the seventh day.
It means: the emperor in the South China Sea is called Shu, the emperor in the North China Sea is called Hu, and the emperor in the center is called Chaos. Shu and Hu often meet in Chaos's residence. Chaos is good for them. Shu and Hu discussed how to repay the kindness of Chaos, saying, "Everyone has seven things to see (outside), hear (sound), eat (food) and breathe (air), but Chaos has no seven things. (Let's) try to open seven tricks for him. " So Shu and Hu knew something about chaos every day. On the seventh day, chaos died.