It originated from Liu Yong's rude remarks, which offended court officials. Renzong just left him as foreign minister in other places. The Oracle said, "Minister in white, write lyrics before the wind and under the moon."

The "white skirt" in the "white skirt" refers to the clothing of civilians and also refers to civilians; "Qing Xiang" refers to senior officials, and in ancient times, it refers to Jinshi. In the Tang dynasty, people attached great importance to Jinshi, and most of the prime ministers were born in Jinshi. Therefore, Jinshi is regarded as a white minister, which means that although he is a white man, he enjoys the wealth of Qing Xiang.

The original sentence should mean that Liu Yong was allowed to be a literati who wrote poems in the moonlight. Although he enjoyed the common hope of the Qing court, he was actually powerless. Since then, Liu Yong's dissolute behavior seems helpless.