Why did Qin Qiong become a goalkeeper?

The gatekeeper is the idol at the entrance of China residential buildings and Buddhist Taoist temples, which has a long history. Door gods are mainly posted on the front or back doors, and Buddhist and Taoist temples also have statues of door gods outside the mountain gates. Door gods are one of the main themes of woodblock New Year pictures. The most popular folklore is that Qin Qiong and Jingde (Weichi Gong) are posted on the left and right doors, while Wei Zhi or Zhong Kui are posted on the single door.

In the novel The Journey to the West, the story of Qin Qiong becoming a caretaker is recorded: the old dragon in Jinghe near Chang 'an made a bet with a fortune teller and broke the dogma. The Jade Emperor sent Wei Zhi to supervise and beheaded the old dragon at 3 noon. The day before, Lao Long asked Tang Taizong to intercede for him, and Tang Taizong readily agreed. The next day, Emperor Taizong announced that Wei Zhi had entered the DPRK and left Wei Zhi to accompany him to play Go. Unexpectedly, at three o'clock at noon, Wei Zhi dozed off and dreamed of beheading the old dragon. Lao Long resented Emperor Taizong's treachery, pestered him, and made trouble in the palace every day, which made the six gods of Emperor Taizong uneasy. Knowing that the emperor was afraid, Wei Zhi sent two generals and Weichi Gong to guard the palace gate. Sure enough, the old dragon dared not make trouble. Emperor Taizong, mindful of their hard work in guarding the door at night, asked the painter Wu Daozi to draw portraits of two people and stick them at the palace gate, but the result still worked. As a result, this move began to spread among the people, and Weichi Gong became a keeper.