This poem "May you always be like the moon in the sky, bright and unstained through the ages" was not written by Emperor Qianlong, but came from the Ming Dynasty writer Yang Shen's "Linjiang Immortal: Rolling Waters of the Yangtze River East" a sentence in a word. This poem expresses wishes for friends or relatives, hoping that they can be as bright and bright as the bright moon in the sky, never being stained by dust, implying good wishes for purity and noble character.
There are also many beautiful verses in Emperor Qianlong's works, but this sentence was not written by him.