Topic on discussion of vital-qi corresponding to heaven in the plain questions (Third article part VIII) [1]

The yang qi dominates the outside in daytime. It engenders at dawn, and blooms at midday. When the yang qi has weakened at dusk, the sweat pores are closed. So men should astringe the yang qi to repel evils after dusk. Do not harass the sinews and bones, nor expose to dew or fog. If one infringes these rules in that three times, the body will become weary and weak.

Key Words: discussion of vital-qi corresponding to heaven, in the plain questions