That which is bright rises twice:
The image of Fire.
Thus the great man, by perpetuating this brightness,
Illumines the four quarters of the world.

Each of the two trigrams represents the sun in the course of a day. The two together represent the repeated movement of the sun, the function of light with respect to time. The great man continues the work of nature in the human world. Through the clarity of his nature he causes the light to spread farther and farther and to penetrate the nature of man ever more deeply.