It means combining leniency with severity, which is the king's way of governing the country. Now it is used to describe the tension of life and the reasonable arrangement of work and rest.

Origin of idioms: The Book of Rites? Miscellaneous notes: "Zhang is not relaxed, civil and military can also be; Easy and not open, both civil and military. The first is to relax, and the way of civil and military affairs is also. "

Example of Idiom: He is also a person who is good at regulating the brain.