《资治通鉴·汉纪·汉纪二》
谈到宋义劝说项羽，先让秦、赵两国相斗，待秦军疲惫后再乘机攻秦，自己却终被项羽杀了，与卞庄子刺杀老虎时，管竖子劝他等待两虎与牛相搏，双方有伤亡时再乘机刺虎，卞庄子最后果然获得二虎，两次的游说之辞也都相同。但这套说辞，施用在战国时，邻国相互攻伐，没有临时情势变化的危急发生，还是可以的。
及宋义待秦、赵之毙，与昔卞庄刺虎同说者也。施之战国之时，邻国相攻，无临时之急，则可也。
When Song Yi persuaded Xiang Yu to let Qin and Zhao fight first and then attack Qin when the Qin army was exhausted, he himself was eventually killed by Xiang Yu. It was similar to when卞庄子 assassinated the tiger, and Gu Shuzi advised him to wait until the two tigers fought with the ox, and when both sides were injured, he could seize the opportunity to assassinate the tiger. 卞庄子 eventually obtained two tigers, and the two persuasions were similar. However, this kind of persuasion was acceptable in the Warring States Period, when neighboring countries attacked each other, and there were no urgent changes in the situation.