《史记·七十列传·张仪列传》
卞庄认为他说的有道理，站在旁边等待它们，不久，两只老虎果然打起来，结果大的受了伤，小的死了，庄子追赶上受伤的老虎而杀死了它，这一来果然获得了杀死双虎的功劳。
卞庄子以为然，立须之。有顷，两虎果斗，大者伤，小者死。庄子从伤者而刺之，一举果有双虎之功。
Bian Zhuang thought what he said made sense and stood by, waiting for them. Soon, the two tigers really fought with each other, and in the end, the bigger one was injured and the smaller one died. Zhuangzi chased after the injured older tiger and killed it. In this way, he indeed earned the credit for killing the two tigers.