In Xu Sheng's inscription, there is a poem by Jiuxianshan, "Purple from the East is true". Oriental purple gas refers to oriental purple gas, which comes from the legend of Laozi's departure from Hanguguan, meaning Ziyang.
Legend of the Immortals records that one day, when Yin was ordered to pass the Hangu Pass, he saw a purple gas coming from the east-this is the origin of our common temple Taoist temple, and there was a flat forehead hanging on the Taoist temple, so he insisted that there must be a saint who passed this pass. I decided to ask him for help. Sure enough, in a short time, an old man with white hair and beard rode a green cow and walked slowly to Hanguguan. This is Lao Zi. Guan Lingyin asked Lao Tzu to die, but Lao Tzu didn't give an ultimatum, so Guan Lingyin asked Lao Tzu for "bad rules." The so-called "bad rules" are what we call bribery today, which also shows that China has a long history of bribery. Lao Tzu is a rich man. How could he possibly take bribes? Knowing that Lao Tzu had no money, Xi said to Lao Tzu, "You can do without money. As long as you can preach to me, I will let you pass. " So, I stayed in Hangu all night and wrote this 5,000-word Tao Te Ching for Guanyin Xi. Xi got the Tao Te Ching and let Lao Zi go out of Hangu Pass.