The origin of "Wen" surname

According to legend, in a certain dynasty, a certain prime minister surnamed Wu was killed by plants in a certain year because of regime change. One of them fled to Wucheng, Jiangsu, and lived in seclusion. One day, a member of the family came to town to ask for news. He happened to meet a famous local fortune teller and took a test immediately. The fortune teller said that your surname is not good, and you have a mouth above the son of heaven.