《左传·襄公·襄公九年》
知罃说： 答应他们结盟然后退兵，用这样的办法引诱楚国人进攻郑国，使楚国人疲劳。
知武子曰： 许之盟而还师，以敝楚人。
Zhi Yan said: Promise to make an alliance with them and then withdraw the troops, and use this method to lure the Chu people to attack the state of Zheng, making the Chu people exhausted.