Meaning:

Gauge: compass; Moment: A ruler. Metaphor means to follow certain rules when doing things.

Source:

Zou in the Warring States Period wrote in Mencius Li Lou: "If you stay in the building, you will lose your son. If you don't obey the rules, it is not Fiona Fang. "

Rules, Fiona Fang's instrument, the moment is square, the rules are round, and the rules are followed. Fiona Fang is. This means that Fiona Fang's vocabulary is meaningless without rules. His inner causality conforms to the general law of the development of things to a certain extent, so people extend it to all aspects of dealing with people and doing things, and teach future generations: without rules, you are not Fiona Fang, which has gradually become the motto of "wise man" in traditional culture.