Know yourself and yourself.

The original intention of knowing yourself and yourself is that if you know both sides thoroughly, you will be invincible in the battle.

Know the earth, know the sky, know the earth: terrain: sky: weather. Understand the terrain and climate.

Knowing the root of the matter means having a deeper understanding.

The original intention of knowing ourselves and ourselves is that if we can thoroughly understand the situation of both sides, we can be invincible in the battle.

Know cold and heat, care about your daily life and take good care of it.

Knowing books and manners, being literate and polite. It is described as educated.

Know heaven and earth: weather; Land: topography. Know the terrain and the climate.

Know the micro, know the micro: small, microscopic: obvious. We know both the tiny budding state and the remarkable characteristics after development. Describe the whole story. Also known as "knowledge chapter" and "knowledge chapter".

Understand the tiny budding state and the remarkable characteristics after development.

Knowing each other is knowing each other, and the heart is connected.