The beauty of Chinese Herbal Medicine is illustrated in line 30 of the Shang Han Lun.
Line 30 Question: In a pattern similar to yang dawn
Using the concept of xiang, or images, we can refer to something in terms of the Dao. In doing so we can see its manifestation.
Yang dawn is the time of day when the sun starts to rise. A pattern that is similar to yang dawn refers to this time period. It also refers to its treatment method, time of day, time of year, and directions.
This is all possible because Dao takes nature as model.
The four models of Laozi, Humans take the earth as model, the earth takes the heavens as model, the heavens take the Dao as model, the Dao takes nature as model.
In the early morning the yang qi starts to rise. The starting point is the shao yin. In tai yin the yang qi is in storage. When the time of shao yin comes, in the period of zi, we see the return of yang qi, as illustrated in the hexagram fu.
The yang line in this hexagram illustrates the return of yang qi. This occurs at 23:00 at night.
Shao yin controls the pivot of fire and water, and yang and yin. The yang qi, when strong, starts to grow, and this continues to the jue yin. The jue yin closes the yin levels of tai yin and shao yin, which gives rise to the growth of yang qi.
The growth that started in shao yin and continued in jue yin, then continues in shao yang.
The shao yang period starts at 3:00 in the morning. It corresponds with the hexagram tai.
Tai contains the all yang trigram on the bottom, illustrated by three yang lines. It contains the all yin trigram on the top, illustrated by three yin lines. We see the tai yin on top of tai yang. This illustrates earth on top and the heavens below.
Hexagram 11 is named 泰 (tài), “Pervading”. Other variations include “peace” and “greatness”. Its lower trigram ☰ qian means force, or heaven, and its upper trigram ☷ kun means field, or earth.
Shang Binghe commentary, Yang naturally rises, yin naturally descends. Because yin is above and yang below, their qi transmits and exchanges, becoming tai. Tai means unobstructed passage.
Tai means unobstructed passage, refers to the normal exchange of yang and yin.
The growth of yang continues from the shao yang to the tai yang. Tai yang opens.
When tai yang fails to open we see the pattern called yang dawn. Yang dawn refers to the time when yang qi starts to grow, and to its treatment, when this fails.
When tai yang fails we see the tai yang wind strike pattern. We can treat this pattern with the herbal formula of gui zhi tang.
A yang dawn pattern refers to the formula gui zhi tang, because this formula restores the normal manifestations of the Dao.