As a divinatory line, nine at the first place of After Completion reads within the hexagram's overall concern with progress in small matters, advantage in being firm and correct, good fortune at the beginning but there may be disorder at the end. The line occupies a place proper to 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 dragging back the wheel of his carriage and wetting the tail of a fox, no error, is the particular fortune assigned to this one stage of the situation, not to the hexagram as a whole.
The first line corresponds by classical convention with the fourth line, and the two correspond here, since one line is yin and the other yang. Read together with the trigram it belongs to, Li in the lower position of the figure, the line marks the opening of the situation, before the trigram above it has any part in the reading, 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 first line of After Completion turns Li into Gen while the other trigram, Kan, stays as it is, which yields After Completion's changing partner, Obstruction (King Wen 39), the hexagram this line is recorded as transforming into.