THE SIGN:

Trigram K'un, the Receptiveabove K'un the Receptive, Earth
Trigram K'an, the Abysmalbelow K'an the Abysmal, Water

This hexagram is made up of the trigrams K'an, water, and K'un, earth, and thus it symbolizes the ground water stored up in the earth. In the same way military strength is stored up in the mass of the people--invisible in times of peace but always ready for use as a source of power. The attributes of the two trig rams are danger inside and obedience must prevail outside.
Of the individual lines, the one that controls the hexagram is the strong nine in the second place, to which the other lines, all yielding, are subordinate. This line indicates a commander, because it stands in the middle of one of the two trigrams. But since it is in the lower rather than the upper trigram, it represents not the ruler but the efficient general, who maintains obedience in the army by his authority.