Many people understand "as long as the moon" as "as long as the moon", which is a misunderstanding.
The word "unchanged" in this language is not "unchanged" in the sense of "permanent", nor is it pronounced as héng? Read gèng.
So what does this mean? It is the "constancy" of "monthly constancy". The Heng Yue orbited the moon for the first time. "Constant as the bright moon" is like the gradual perfection of the first quarter moon, and "Rising Sun" is like the newly rising sun, which is often used to indicate that it is in a prosperous period, and it also means that it has strong vitality and broad development prospects.
Today, this phrase is often used to congratulate people. If used to congratulate people, it means to wish them career development.
This sentence comes from the Book of Songs Xiaoya Tianbao: "If the moon remains unchanged, if the sun rises, it will be like the life of Nanshan."