司空见惯 — “A common occurrence or sight”

During the Tang Dynasty, there was a highly accomplished poet and essayist named Liu Yuxi. After passing the imperial examination and becoming a Jinshi, he served as an Imperial Censor in the capital. However, due to his unconventional and unrestrained personality, he was ostracized and demoted to the post of Prefect of Suzhou.

During his tenure in Suzhou, a former official who had held the title of Sikong (Minister of Works), named Li Shen, admired Liu Yuxi's reputation and invited him for a banquet, where several courtesans were present. During the drinking, Liu Yuxi, in a moment of poetic inspiration, composed a poem which included the lines: "With lofty buns and cloud-like hair, a new fashion, a spring breeze tune from Du Weinang. The Sikong sees it as common, but it breaks the heart of the Suzhou Prefect."

The idiom "Sikong Jian Guan" (司空见惯) is derived from this poem. In this poem, "Sikong" refers to an official title during the Tang Dynasty, equivalent to the Minister (Shangshu) in the Qing Dynasty. From Liu Yuxi's poem, the entire idiom means that Minister Li (Sikong) was so accustomed to such occurrences that he found them unremarkable.

This is a widely used idiom, but many people still misuse it. It cannot be used for naturally occurring phenomena, such as the sun rising in the east in the morning and setting in the west in the evening; one cannot say "Sikong Jian Guan" for these.

However, it is appropriate for accidental events that happen frequently, especially when observed repeatedly. For instance, in bustling city streets, vehicles usually travel safely, but accidents often occur, injuring people or damaging cars. When we see such incidents frequently, using "Sikong Jian Guan" is fitting.