In ancient China, dates were recorded by heavenly stems and earthly branches. There are ten numbers in the heavenly stems and twelve numbers in the earthly branches, so the heavenly stems and earthly branches are matched, and every sixty days is a cycle. At this time, there were six Geng days, which were named noon, morning, yin, zi, Xu and Shen respectively, among which Japanese was one of the six Geng days.
According to Taoist theory, on the night of Gengshen Day, three corpses in the human body will leave the body and fly to the sky to report their merits and demerits, and then the Emperor of Heaven will reward and punish them according to the merits and demerits. Therefore, if they insist on keeping vigil on the night of Gengshen Day, the three corpse gods will not be able to fly to the sky to report for duty, so the custom of Taoist priests keeping Gengshen came into being.
Keeping Geng Shen is a way for Taoism to get rid of three death.
Keeping Gengshen, as the name implies, is to keep vigil on Gengshen Day to eliminate the three corpses, so it is also called keeping the three corpses. In ancient times, the Three Corpses were also called Three Corpses, Three Corpses God or Three Corpses. According to Wei Shu of Han Dynasty, there are three corpses in human body, which can kill people. Therefore, people who seek immortality need to go to the three corpses and accumulate all the virtues before they can become immortals.
Taoism, on the other hand, inherits this view and regards the disposal of the three corpses as the first priority of becoming immortal. Taoist books handed down from ancient times to the present record the methods of eliminating the three corpses, such as taking medicine, spells, keeping Geng Shen, avoiding the valley and being convinced, and so on.
One of the most important things is to keep Geng Shen, that is, don't stay up late on Geng Shen day, sit still and wait for you, and don't let the three corpses report to the Emperor of Heaven, so as to get rid of the three corpse gods.