老子去看常枞。常枞张其口而示老子曰：“吾舌存乎？”老子曰：“然。”“吾齿存乎？”老子曰：“亡。”常枞曰：“子知之乎？”老子曰：“夫舌之存也，岂非以其柔耶？齿之亡也，岂非以其刚耶？”常枞曰：“嘻，是已。天下之事已尽矣，无以复语子哉！”老子的意思是刚易折，柔 I see often fir. Often fir Zhang mouth and said I said: “I tongue exist?” Lao Tzu said: “However.” “My teeth exist?” Lao Tzu said: “Death.” : “Fu husband’s tongue also, is it not his tender teeth? The death of the tooth also, is it not just its just that?” Often fir: “hee, is already. ”I mean just easy to fold, soft