To Show Off One's Skill With an Axe In Front of Lu Ban's Door

The great Tang dynasty pot, Li Bo, was an outspoken and romantic type of person. He loved a good time, and he often went out drinking with his friends. One time, when he and some friends were out boating, Li Bo got dead drunk, fell into the river, and drowned.

After Li Bo's death, many people who felt themselves to be geniuses would go and inscribe poems in front of his tomb. The scholar Mei Jr-huan felt that these people were highly overrating their own abilities. So, after all of their poems, he added another one, the meaning of which was: "Here lies Li Bo, a poet who will go down in history, Inscribing one's poem in front of his tomb is the same as showing off one's skill with the axe in front of Lu Ban's door."

This "Lu Ban" that Mei Jr-huan mentioned was a famous craftsman of the Spring and Autumn Period who was very skilled with the axe. So, "to show off one's skill with the axe in front of Lu Ban's door" means of flaunt one's ability in front of an expert. Proving that one doesn't know one's own limitations. Sometimes, we can slo use this idiom as a polite expression, indicating that the people to whom we are speaking are much more talented than ourselves.

班門弄斧

“班門弄斧”這則成語的班是指魯班，我國古代的巧匠。魯班，又名魯般、公輸般。春秋時代魯國（今山東曲阜）人。傳說是位能工巧匠，善於雕刻與建築，技藝舉世無雙。人們一直把他看作是木匠的祖師爺。

有一次，明代詩人梅之煥來採石磯憑吊李白。採石磯是民間傳說中著名唐代詩人李白晚年遊覽採石江時，見水中之月，清澈透明，竟探身去捉，便墮江而歿的地方。由於李白在此留下過足迹，因此傳說紛起，並留下了不少名勝，如李白墓、謫仙樓、捉月亭等等。採石磯也因此成了旅遊勝地。

這天，梅之煥來到採石磯旁的李白墓，一看卻心中大爲不滿，磯上、墓上，凡墓前可以寫字的地方，都被人留有詩句，那些寫文章狗屁不通，卻想冒充風雅的遊人，竟在被稱爲“詩聖”的李白的墓上胡謅亂題，那些拙劣詩句的作者，又有甚麽臉在李白面前舞文弄墨呢？真是可笑之極！梅之煥心中越想越不是滋味，感慨之餘，揮筆題了一首詩：“採石江邊一堆土，李白之名高千古；來來往往一首詩，魯班門前弄大斧。”

“班門弄斧”最早出現的雛形是柳宗元的“操斧于班、郢之門，斯強顔耳”。意即在魯班門前操弄斧子，是厚著臉皮。（郢，是另一位古代的操斧能手）諷刺那些不自量力，竟在行家面前賣弄本領的人。梅之煥譏諷那些自以爲會作詩的遊人，是“魯班門前弄大斧”。

這句話被後人縮成“班門弄斧”。這樣，“班門弄斧”的成語，就流傳下來了。