"When the strike of a hawk breaks the body of its prey, its because of timing. Strike the enemy as swiftly as a falcon strikes its target. It surely breaks the back of its prey for the reason that it awaits the right moment to strike; its movement is regulated.
When torrential water tosses boulders, it is because of its momentum; thus the momentum of one skilled in war is over-whelming, and his attack precisely regulated. His potential is that of a fully drawn crossbow; his timing, the release of the trigger."