Du Fu, a poet in the Tang Dynasty, wrote two poems for the road, "March 3 is Chang 'an city shore, March 3 is sunny."

Du Fu, a poet in the Tang Dynasty, wrote the poem "Second, Taoism" as "The weather is sunny in the third day, and there are many beautiful people by Chang 'an water." In China, "March 3rd" is the last festival.

Shangsi Festival: commonly known as March 3rd, is a traditional festival of the Han nationality. It was designated as the fourth day of March before the Han Dynasty, and was later designated as the third day of March in the summer calendar. Shangsi Festival is the most important festival in ancient times. People go to the water to take a bath together, which is called "praise" Since then, sacrificial banquets, meandering water and outings have been added.

In ancient times, it was marked by "dry branches", and the first day of March to the fourth day of March was called "thinking". The word "Shangsi" first appeared in the documents of the early Han Dynasty. "Zhou Li" Zheng Xuan commented: "If you get rid of it when you are old, this is like water in March." After Wei and Jin Dynasties, the festival of Shangsi Festival was changed to the third day of the third month of the lunar calendar, so it was also called "Chongsan" or "March 3".

There is a saying in Shangsi Festival that witchcraft originated from blue soup to ward off evil spirits, and blue soup is used to ward off evil spirits. Bluegrass, as a spiritual thing, has the characteristics of aroma. The ancients fasted before holding a major ceremony of offering sacrifices to the gods, including the best bathing method at that time, "blue soup bathing".