What are the five elements, seven orifices, nine days, Tai Chi, eight diagrams, twenty-eight nights and great Yan?

This is about ancient astrology, divination and so on.

The five elements refer to gold, wood, water, fire and earth.

Tai Chi gives birth to two instruments, two instruments give birth to four images, and four images give birth to gossip. Eight, eight and sixty-four hexagrams contradict each other and have been deduced countless times.

In ancient China, in order to study astrology, the sky was divided into several regions, so there was one.

The flow of seven days and nine days