In contemplation, nothing is clearer than being close. The fifth line occupies the honored position with firm, yang, central correctness; it is a sage and worthy ruler.
The fourth line is immediately adjacent to it, observing and seeing its dao; hence it is said: "Contemplating the light of the state," which means beholding the glorious splendor of the state's abundant virtue.
It does not refer to the ruler's person directly but says "the state," because for a ruler, how could one merely observe the conduct of his single person?
One should observe the governance and transformation of all under heaven, and then the virtue and dao of the ruler can be seen.
Although the fourth line is yin and yielding, it belongs to the Xun trigram, occupies Correct Position, and is immediately adjacent to the fifth; it observes and is able to comply.
"Advantageous to be a guest of the king": when a sage and enlightened ruler is on high, people endowed with talent and virtue all wish to enter the court, to support and assist him in bringing peace and succor to the world.
Having observed the virtue of the ruler and the magnificent brilliance of the state's governance, the fourth line ought to be received as a guest at the royal court, devoting its wisdom and strength to assist the ruler on high and dispense beneficence to all under heaven.
Hence it is said: "Advantageous to be a guest of the king." In antiquity, when there was a person of worthy virtue, the ruler treated him with the courtesy due a guest; thus, a scholar entering official service at the royal court was termed a "guest."