As a divinatory line, nine at the fourth place of The Arousing reads within the hexagram's overall concern with ease and development; when the movement comes the subject looks out with apprehension, and yet is found smiling and talking cheerfully after, for the shock terrifies for a hundred miles while he does not let fall the sacrificial spoon and cup. The line occupies a place that does not match its own nature in the classical doctrine that odd places favour a firm, yang line and even places favour a yielding, yin line. Its own text, that the shock leaves him sunk in the mud, is the particular fortune assigned to this one stage of the situation, not to the hexagram as a whole.
The fourth line corresponds by classical convention with the first line, and the two do not correspond here, since both lines share the same character. Read together with the trigram it belongs to, Zhen in the upper position of the figure, the line marks the first word of the upper trigram, close enough to the ruling fifth line to be shaped by it, one stage in the six stage movement the hexagram traces from its first line to its last.
A change at this line, from yang to its opposite, is the mechanism the tradition uses to move from one hexagram to another. Flipping the fourth line of The Arousing turns Zhen into Kun while the other trigram, Zhen, stays as it is, which yields The Arousing's changing partner, Return (King Wen 24), the hexagram this line is recorded as transforming into.