Yuan Gaoming, Pipa Story, Niu Jiaonv. Rudder (z m 4 n rudder): I have to hurry. Time is like an arrow, urging people to get old, and the sun and the moon are like weaving shuttles, forcing away youth. This famous saying uses two metaphors to describe the flight of time. The former is compared to the speed of an arrow, while the latter is compared to the speed of a shuttle, which vividly shows the invisible, intangible and eternal characteristics of time. Because of its vivid description, vivid sentences, flying literary talent and appealing to both refined and popular tastes, famous sentences have been circulated among the people. However, the word "qi" in the second sentence is not very popular, so the folk changed it to "catch" Yu, which is completely colloquial, thus making this famous sentence more vital.