In the Spring and Autumn Period (chūn qiū 春秋时期,770-476 BC), there was a beauty in the State of Yue called Xishi (xī shī 西施). She often suffered from pains in her chest, and so she would often walk around doubled over and with her brows knitted. There was an ugly girl in the village called Dongshi who envied Xishi. Striving to emulate Xishi, she imitated her stoop, knitting her brows at the same time. She thought that this made her elegant, but in fact, it only made her more ugly.
Later, this idiom came to be used to indicate improper imitation that produces the reverse effect.

Wang Xizhi (wāng xī zhī 王羲之) is one of the most famous calligraphers during the Eastern Jin Dynasty (dōng jìn 东晋,AD 317-420) of China. When he was very young, he practiced his art every day and never stopped. Later he absorbed the strong points of all the other schools of calligraphy, and developed his own unique style of writing. Because of his achievements, he has been honored as one of China's sages of calligraphy. It is said that a carpenter once found that the ink of the characters Wang Xizhi had written had gone almost one centimeter into the wood because of his forceful stroke." Rù Mù Sān Fēn" is got from this story, which means the calligraphy is penetrating. Now it is often used to describe expressing sharp ideas or profound views.