法苑珠林 31.51

31.51

魯昭公十九年。龍鬪於鄭時門之外洧淵。京房易傳曰。眾心不安。厥妖龍鬪其邑中也。

In the nineteenth year of Duke Zhao of Lu, dragons fought at the Wei Deep outside the Shimen Gate of Zheng. Jing Fang's Commentary on the Changes states: “When the minds of the multitude are uneasy, the portent is that dragons fight in their city.”