班bān门mén弄nòng斧fǔ

Literal: to wield the axe before (Lu) Ban's gate
Figurative: to show off one's meager skill before a true master.

Where does 班门弄斧 come from?

Lu Ban was the most legendary carpenter of ancient China, an unrivaled master of the axe. Hence the saying: to brandish an axe at Lu Ban's very gate is to flaunt a skill before the one who commands it supremely, a gesture as futile as it is absurd.

How is 班门弄斧 used? Two examples

在zài这zhè么me多duō语yǔ言yán学xué家jiā面miàn前qián谈tán语yǔ法fǎ，我wǒ真zhēn是shì班bān门mén弄nòng斧fǔ了le。
Talking about grammar in front of so many linguists, I'm really showing off before the masters.
您nín是shì这zhè方fāng面miàn的de专zhuān家jiā，我wǒ就jiù不bù班bān门mén弄nòng斧fǔ，献xiàn丑chǒu了le。
You're the expert here, so I won't flaunt my poor skills before a master and embarrass myself.

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