蜀中有杜處士 ，好書畫，所寶以百數。有戴嵩《牛》一軸，尤所愛，錦囊玉軸，常以自隨.。一日曝書畫，而一牧童見之,拊掌見笑，曰：“此畫鬥牛也，牛鬥力在角，尾搐入兩股間。今乃掉尾而斗，謬矣！” 處士笑而然之。

A hermit in Sichuan named Du was fond of paintings and owned a hundred collections he treasured. In Particular, he liked a scroll of "Bull," printed by Dai Song, which he wrapped with embroidered silk and decorated with jaded axes and brought with him all the time. One day, he bathed the painting in the sun, and a cowherd saw it and smiled while clapping his palms, "You draw a fighting bull, but when a bull is fighting, its tail should shrink between its thighs; now it waggles its tail in fighting. You made a mistake!" The hermit acknowledged with a knowing smile.

古語云：“耕當問奴，織當問婢。”不可改也。

As an old saying goes, " Ask farming from a peasant; ask knitting from a weaver." It stands.