The next second, the entire hall shook.
Then, a gentle and righteous male voice sounded.
…
[Yin and Yang, the Dao of Heaven and Earth, the outline of all things, the parents of change, the beginning of life and death, the residence of the Gods.]
…
Zhou Zhou nodded slightly.
This is from the Yellow Emperor's Internal Cultivation: The manifestation of Yin and Yang from the macrocosm to the microcosm.
What it meant was that Yin and Yang were the general rules of the universe. They were the outline of everything, the origin of the changes in all things, and the root of the growth and destruction. There was a lot of logic in it. Anyone who treated illnesses had to find the root of the change in the illness.
Then, he looked at the following text notification.