Meaning: Don't attempt something beyond your abilities, for it will only end in failure.
Source: Zhuangzi (Chuang Tzu)
1.At the end of the Spring and Autumn era Yan He, a man of letters from the state of Lu, traveled to the state of Wei, where King Ling Gong offered to make him tutor to his son Kuai Kui.
2.Kuai Kui had a violent temper and would kill people at the drop of a hat. Yan reckoned that if he accepted the post as tutor and let Kuai Kui do as he pleased, the nation would suffer, but Yan knew that if he tried to stop Kuai Kui, he would put his own life at risk. With this dilemma he went to the minister Qu Boyu for advice.
3.Qu told Yan this story: "One day I took my chariot out for a ride and suddenly saw a mantis on the road angrily raising its arms to stop the chariot's advance."
4.But the chariot didn't change course, and the poor mantis was crushed.
5.Qu continued, "The mantis' tragedy was in not knowing the limits to its own strength-just like you today. You think you will be able to change Kuai Kui's evil ways, and as a result you may end up just like the mantis."
6.Yan saw the logic to what Qu had said and decided not to take the post, requesting to leave the state of Wei as early as possible. Later, Kuai Kui's misdeeds led someone to kill him.