Most importantly, the only way is eternal, reciprocating and never changing.
The Tao here can be understood as a rule, and the sky can be said to be the rule of heaven and earth, which is a perfect circle. Never changed.
The main performance here is that when people are alive in time, they are always repeating a rule. If you work hard, you will get something, and if you are lazy, you will starve. Good people are rewarded, and bad people are rewarded. This should be an understanding of Tao. Personal understanding is different. But the highest level of individuals will be the same.
Connected with this sentence can be
Heaven and earth are ruthless, and everything is a dog. The former is more peaceful and the latter is more radical. Resigned and resigned tone.