Indian yoga and Taoist mystical practice provide people with precise soul control. It is the immortality of body and spirit. Su Dongpo is obsessed with the pursuit of immortality. The ancients, from the emperor to the ordinary people, all wanted to live forever. I think people nowadays know what they can't do, not what they don't want to do.
Immortality is also called "keeping in good health" or "an alchemist" in China. The danger sought are both internal and external. "Inner Dan", according to the Taoist method, is to practice the part below the navel; "External medicine" is the elixir of life sought by alchemists in China.
Although Su Dongpo pursues, explores and is fascinated by yoga and immortal art, he knows the limits. Too much is too late. The most important component of Vaidan is an amalgam. In this respect, it is similar to European alchemy. Many people died because of experiments or taking the wrong prescription by mistake. Although Su Dongpo is particularly interested, he is also particularly alert. Su Dongpo himself eats two other foods, Poria cocos and sesame. At that time, it was considered as the food of the immortal family. I think it's because Taoist priests live in the mountains and it's difficult to find other food. The farther plants grow, the greater the difference between them and ordinary grains, and the more they will be considered as immortal food. Although Su Dongpo wants to live forever, he is not fascinated. In a letter to Li Chang, he discussed moderation and simplicity from a natural perspective. Let's put aside the quest for Dan, forget the useless pursuit and return to a simple and temperate life. People just need to follow common sense. Temperance is the only lasting method.
The essence of yoga is rest, which is planned and you will feel rested. Yoga is characterized by complete physical and mental rest, and then through various ways to control breathing and increase oxygen intake. Su Dongpo mentioned in his letter to his younger brother Ziyou: After being freed from the senses, the real understanding of truth, or of God, or of the soul of the world lies not in what you can see, but in what you can't see. Su Dongpo also endowed yoga with several China elements. He not only ruled out stunts and other grotesque soft body movements, but also added regular spitting, which was completely derived from Taoist physiological experience. This is also in line with Su Dongpo's temper.
Su Dongpo in this chapter is a poet who practices yoga, alchemy, meditation yoga and seeks longevity.