One word of gold comes from Historical Records and Biography of Lv Buwei: "The gate of Xianyang, Bu, hangs thousands of gold, and those who can increase or decrease one word will be given thousands of gold." It means that one sentence is worth 1000 yuan. Originally, it means to change a word and give 1000 yuan. After seeing it, it is used to praise the exquisiteness and high value of poetry. It also refers to the preciousness of calligraphy works.
The source of Yunnan source
"Cloth Xianyang City Gate, hang a thousand dollars on it, and extend the princes to give a thousand dollars to those who can increase or decrease a word."