The fifth is normally the ruler's position; however, the symbolism of the *Changes* shifts and transforms with the times. Six at the Top dwells at the summit of Kun, the very culmination of Darkening of the Light—the extreme of yin darkness that wounds brightness.
Line 5 is adjacent to it. The sage therefore took Line 5 as one standing close to supreme darkness to illustrate the principle of conduct; he did not speak solely of the ruler's position.
Six at the Top is the extreme of yin darkness wounding light, hence regarded as the master of Darkening of the Light. Line 5 is adjacent to this ruler who wounds brightness; if it displays its light, it will surely be harmed.
Therefore, one must emulate Jizi in obscuring and hiding oneself, thereby avoiding calamity. Jizi was an elder minister of Shang and a royal kinsman of the same surname, truly intimate with King Zhou. Had he not obscured his brightness, suffering disaster would have been certain.
Thus he feigned madness and became a slave to escape harm. Though concealing his brightness, he guarded his rectitude within; this is what is meant by "bearing inner trouble yet able to keep one's will correct," which is why he was called benevolent and wise.
One like Jizi may truly be called persevering. Because Line 5 is yin and yielding, the warning is given: "beneficial to be steadfast," meaning one should be as firm and steadfast as Jizi.
If interpreted through the ruler's way, the principle is the same: when a sovereign must hold back and veil his brilliance, he too obscures his light externally while rectifying his will within.