During the reign of Emperor Wu of Jin Dynasty, Cui Hong, the official minister, recommended him as the left prime minister. Later, when he became the secretariat of Yongzhou, Emperor Wu of Jin asked him about his evaluation. He said, "I am like Guizhi in the Moon Palace and Baoyu on Kunlun Mountain." A laurel in Guanghan Palace and a Pian Yu in Kunlun Mountain are used to describe particularly outstanding talents, which is the origin of "the laurel of the moon". The moon is the moon palace. Emperor Wu of song laughed and praised him. After the Tang Dynasty, the imperial examination system prevailed, and the laurel of the moon was used as a metaphor for scholars who passed the examination.
Moon: Moon Palace. Fold laurel; Broken osmanthus, osmanthus moon palace. There was a three-legged toad in the Moon Palace in Han mythology, and later people also called the moon the Moon Palace. Osmanthus fragrans climbing the Moon Palace. Metaphor should be successful in the imperial examination era. The ninth time in A Dream of Red Mansions: "At that time, Daiyu was dressing in the mirror under the window. Baoyu said he would go to school. Baoyu said with a smile, "OK, I'll go, but I won't see you off because of the honor under the moon." Also known as "Moon Class Regulations".