《易传·象传下·未济》
 小狐狸渡河时被水浸湿了尾巴 ，说明其自不量力，不知道自己究竟能使多大的气力，急躁冒进，结果招致麻烦。
贞吉悔亡，志行也。君子之光，其晖吉也。饮酒濡首，亦不知节也。
When the little fox crossed the river, its tail got wet, indicating that it was overestimating its own abilities, not knowing how much strength it could exert, being impatient and impulsive, and eventually causing trouble.