Zài Lǔbān miànqián shuǎ fǔtou, nà shì bānménnòngfǔ.
Wielding an axe in front of Lu Ban — that's showing off in front of an expert.
Tips
history
Credited with inventing the saw, the carpenter's square, and the cloud-ladder siege engine. Many legends, little confirmed history — he is more cultural icon than documented figure.
culture
The idiom 班门弄斧 ('to wield an axe at Lu Ban's gate') means to show off skill in front of a true expert — still extremely common in modern Chinese.
