Yang Qi and Yin Qi in nature refer to the growth qi in spring and summer and the gathering qi in autumn and winter respectively, specifically, spring, long summer, autumn harvest and winter storage.
In spring, the yang rises, and what is bred between heaven and earth is the qi of hair growth. Therefore, the living do not kill, the giver does not take away, and the reward does not punish, in order to adapt to the spring. Nourishing yang in spring is to make the body and mind full of vitality, and don't contain it.
In summer, the yang is strong, the yin lies on the ground, and the qi of heaven and earth intersect, which breeds the "Qi Long". Therefore, the key to raising yang in summer is not to hate long days, to pay attention to the will to recuperate, and not to get angry or sad easily, so as to enrich yourself.
"Nourishing yang in spring and summer, nourishing yin in autumn and winter" is a rhetorical method using mutual words in ancient Chinese, which requires that "writing refers to each other and seeing the text refers to something", that is, the upper and lower sentences seem to say two things, which are irrelevant, but in fact they echo each other, explain each other and complement each other. When understanding its meaning, we should integrate the two aspects, not be paranoid and not separate.
This sentence inspires us that people who are good at keeping in good health should adjust Yin and Yang according to the four seasons, keeping in good health in spring, growing in summer, harvesting in autumn and storing in winter.