《战国策·赵一·知伯帅赵韩魏而伐范中》
张孟谈于是暗中进见韩、魏之君说， 臣下听说嘴唇没有了，那么牙齿就要受寒，观在智伯率领二囤之君进攻赵国，赵国将要灭亡了，赵国灭亡那么二君也要依次跟着灭亡。 
张孟谈于是阴见韩、魏之君曰： 臣闻唇亡则齿寒，今知伯帅二国之君伐赵，赵将亡矣，亡则二君为之次矣。 
Zhang Mentan secretly met with the kings of Han and Wei and said, "Your servant heard that if there are no lips, the teeth will feel cold. Now that wisdom has led the two princes to attack Zhao, Zhao will be destroyed, and when Zhao is destroyed, the two princes will be destroyed one after another.