三寸不烂之舌 is used to describe great eloquence, similar to the English phrase "silver tongue". How exactly did this phrase come about? What does "三寸" mean? What's the meaning of "烂" in this phrase?
Some examples of its historical use include:
- 《水浒全传》第十五回:“小生必须自去那里,凭三寸不烂之舌,说他们入伙。”
- 《三国演义》第三回:“愿凭三寸不烂之舌,往江东说此人来降。”
Edit
I'm sorry if this question seems very basic, as I'm getting a few very basic responses. This is what should be obvious (and I'm not asking):
- 三寸 is a length, alluding to the tongue
- 烂 also has the meaning of "worn out"
- The literal meaning of "三寸不烂之舌" would be "a tongue that does not wear out", meaning someone who can speak at length with ease, hence eloquence.
What I'm not clear on, and I'm hoping there are some explanations, are:
- Why use 三寸, a length, to describe the tongue? Why not use something else, like weight or colour? Why use 三寸 to describe the tongue, as opposed to other body parts? What's the significance?
- 烂 has many meanings, so why pick the "worn out" one? Was the meaning of "worn out" more idiomatic during the origin of this phrase, as opposed to what it's usually used for now - tender or rotten? Why not use other characters to mean the same thing, is there a significance to using 烂?
I appreciate that in etymology, sometimes there are no good answers, or there were but are lost to time.