From "The Xiang says: Heaven and Earth interact: Peace" to "to support the people." The Zhengyi commentary says: "The sovereign fashions and completes the way of Heaven and Earth": because all things interpenetrate in peace, above and below may lose moderation.
"Sovereign" (hòu) means the ruler. At this time, the ruler should trim and tailor, bringing the way of Heaven and Earth to completion. "Aids the fitting order of Heaven and Earth": "xiàng" means to assist; he should assist the fitting provisions generated by Heaven and Earth.
"To support the people": "zuǒyòu" means to assist and support, helping to nurture his people. "The way of Heaven and Earth" refers to the four seasons: the principles of winter cold, summer heat, spring generation, and autumn killing.
If their qi simply blends without measure, things lose their moderation. If things lose their moderation, there would be winter warmth, summer chill, autumn growth, and spring killing.
The ruler must tailor, moderate, and bring to completion, keeping cold and heat in their normal cycles, and growth and harvesting in their proper seasons; these are the natural qi of Heaven and Earth, hence called "the way of Heaven and Earth."
"The fitting order of Heaven and Earth" means that the things generated by Heaven and Earth each have what is fitting for them.
As the Minister of Education says, "its animals and plants," and the Official of Geography notes that Yangzhou's fitting tribute is rice and wheat, while Yongzhou's fitting tribute is millet and sorghum.
If heavenly qi were completely undifferentiated, these fitting provisions would be reversed.
Therefore, the ruler assists the fitting things of Heaven and Earth so each rests securely in its nature and finds its suitability; speaking in terms of things, it is called "fitting order" (yí).
This hexagram uses "sovereign" (hòu) because it does not include dukes, ministers, and grandees, so it does not say "noble person."
Yet it encompasses feudal lords, so it cannot simply say "ancient kings"; intending to show that both the Son of Heaven and the feudal lords are south-facing rulers, it specifically says "sovereign."