Why do you want to eat jiaozi during the Spring Festival? What is the origin of jiaozi?

According to legend, it is related to the medical sage Zhang Zhongjing.

One winter was particularly cold, and the north wind roared. Many people suffered from frostbite, and some even lost their ears. In order to treat people, Zhang Zhongjing invented a new medicine, which can be wrapped in dough and eaten as food. It can cure diseases and satisfy hunger. Because it is shaped like a human ear, it is named Joule. Because this kind of food is eaten in the New Year, the new year and the old year are given to children, so it was named jiaozi, and later the word "food" was added next to the word "dumplings", which became today's jiaozi.