A legend is told about the old man under the moon. During the Tang dynasty, there was a young man named Wei Gu (韋固 Wéi Gù). Once he was passing the city of Songcheng, where he saw an old man leaning on his pack reading a book in the moonlight. Being amazed at it, Wei Gu walked up and asked what he was doing. The old man answered: "I am reading a book of marriage listing for who is going to marry whom. In my pack are red cords for tying the feet of husband and wife." When Wei Gu and the old man came together to a marketplace, they saw a blind old woman carrying a three-year-old little girl in her arms. The old man said to Wei Gu: "This little girl will be your wife in the future." Wei Gu thought the girl was not good looking so he sent his servant to stab the girl with his knife.

Fourteen years later, Wang Tai, the governor of Xiangzhou, gave Wei Gu his daughter in marriage. He was having difficulty finding a suitable match of higher standing for his daughter even though she was a beautiful young woman because she had difficulty walking and had a large scar on her back. When Wei Gu asked what had happened, he was told that she had been stabbed by a man in the marketplace fourteen years before.

After ten years and three children later, Wei Gu sought the old man for suitable matches for his two younger sons and daughter. The old man refused to find suitors for his children. During the later years Wei Gu sought to find a possible match for his children but by coincidence, no marriage was put to order.