Where did the phrase "life is like duckweed" and the sentence related to him come from?

"Life is like duckweed" should be a common saying, which is quoted in many poems. For example, "The Mid-Autumn Moon sends a mistress". Shu Zi is in Wenshang, and her family is relatively bright. Zheng Zi went to Heshuo and sailed alone for one night. Although the meal is close at hand, it is like being in prison. Zhao Zi sent a book, and the water was noisy. Four hearts, * * * This is thousands of miles away. The bright moon does not understand the old, and it is difficult to close in an instant. Looking back, sitting on a person, gathering and dispersing like a flowing ping. Smell this moonlit night. Wan Li, clear sky, Wan Li. There are few birds outside Shen Ying's gate, and the elders are willing to find them. Stay, stay and listen to a lonely song. No matter whether you are idle or not, it is a waste of leisure and trouble. But looking at the reflection in the mirror, the temple is already a star. Life is like duckweed. Be sure to drink when you meet, and stay together. When it comes to human feelings, there is no realm of introduction, and wine is a bosom friend. The situation is good, relative and regular.