What does it mean that the sky, the earth, the sun, the moon and the stars come first?

The first section is about the contents of the sky, the earth, the sun, the moon and the stars, so it is called "the sky, the earth, the sun, the moon and the stars come first".

The original Biography of the Duke of Zhou was divided into twenty-seven sections. They are: heaven, earth, sun, moon, stars, geographical rocks and trees, body, face, teeth, clothes, shoes and socks, swords, bells and drums, imperial civil and military calls, palaces, warehouses, doors, stoves, kitchens and toilets, gold and silver, pearls, jade and silk, mirror rings, combs, bed curtains, etc.