"Bigu", also known as Quegu, Qugu, Juegu, Juegu, Jiegu and Jiegu, originated from Fang Xian's "not eating five grains" in health preservation, that is, instead of eating five grains, he filled his stomach with drugs, food and other things, or stopped eating for a certain period of time, which was a common health preservation method of the ancients.
Pigu, often associated with persuasion, is called convincing to Pigu. Being convinced, as the name implies, is to take qi. After being influenced by Taoist thought, it is called taking essence or taking qi. This is the practice of replacing food with qi, and the method of breaking the valley with conviction is always emphasized by Taoism. Since the Han Dynasty, there has been a legend that Taoist priests were persuaded to break the valley, and there were also many imitators in previous dynasties.
There is a legend of "people who eat gas" in Shan Hai Jing, and later there is a saying that "people who eat gas live as immortals". A similar concept was transformed by Zhuangzi into the work of a divine man, and "A Happy Tour in Zhuangzi" contained: "The mountain that takes advantage of the situation has immortals living there."
If the skin is like ice and snow, if you are a virgin, you will not eat grains, suck the wind and drink dew, ride a dragon in the clouds, and travel around the world. "Shooting God doesn't need grains and other grains, but only eats wind and dew.
Begging for grain originated in the pre-Qin period, and it was about the same time as qi-moving. In a etiquette treatise before Qin and Han Dynasties, The Core Monument of Yi Life said: "Carnivores are brave, food eaters are wise, gas eaters live with God, and non-food eaters live with God", which is the earliest theoretical basis for gas eating.
There is a similar record in Huainanzi Terrain Training. After the establishment of Taoism, many people inherited this technology and practiced the valley. From Han Dynasty to Song Dynasty, the art of divination valley was very popular in Taoism. There is a cloud in the Western Han Dynasty's "Going to the Valley to Eat Qi": "Those who go to the Valley will eat Shiwei. If you are heavy-headed, light-footed, and clumsy, you will be smashed (fried), depending on the benefit. "
It means that when you first arrive in the valley, you often have top-heavy hunger, which must be overcome by "blowing". Here, the combination of Bi Gu and Hodge, like the deliberate combination of Hodge and Dao in Zhuangzi, seems to indicate the initial existence of these three technologies in the pre-Qin period, that is, they generally appeared at the same time.