Why is the favor of ancient emperors called "rain dew"?

Ancient emperors called themselves the sons of heaven and were called the sons of heaven.

During the feudal period, the emperor seemed to be a paradise for ministers and people all over the world. Whether it thunders or rains, it is a gift from heaven to mankind.

Therefore, it is better to say that luck is called rain and dew, and it also has a meaning (meaning or meaning entrusted or contained)

It means that it contains providence, and it is a blessing to come to dew (for feudal society).