1. There are only three things that can be done, which comes from the allusion of "one vigorous effort, then decline again, and three times will be exhausted" during the Spring and Autumn Period and the Warring States Period;

2. If you fish in the lake, you will not get something, but there will be nothing next year. If you burn the fields and burn the fields, you will not get fish, but there will be no beasts next year. From "Lu's Spring and Autumn Annals";

3. When the sun is at midday, it will be dark, when the moon is waxing and waning, the sky will be lonely and empty, and the earth will be in the southeast. Quotes from "The Collected Works of Zeng Guofan";

4. If it is too strong, it will be broken, if it is too wide, it will be lacking. Cheng Yi of the Song Dynasty said:

5. When chaos is extreme, there is order; when darkness is extreme, there is light. This is the way of heaven. The words come from Hong Xiuquan's "Yuan Dao Awakening the World" in the Qing Dynasty.