Watch the danger?
When threatened, people tend to keep their eyes on the threat. If an attacker has a weapon, such as a gun or knife, people will tend to concentrate on the weapon as the threat. However, the weapon is an inanimate object; is in itself is not a threat to you; the real threat is the person holding the weapon. If you watch the weapon for a movement, you will die. You must watch the person in control of the weapon so you may anticipate what the person might do with the weapon.
The same holds true for watching a sparring opponent’s natural weapons, his or her hands and feet. If you watch either one, it will probably hit you anyway, and even if it does not, the other one will.
Watch the hands?
When a hand attack fires, the first thing to move should be the hand, actually the hand, arm, and body move almost simultaneously. Actually, this is not always the case since many fighters add other extraneous movements to their attacks, such as personal quirks, habits unknowingly picked up, or even useless movements taught by some pseudo-master in an effort to be different from other martial arts. In any case, if you watch the hands for an attack, once you see a hand move, it is too late to react; the hand is already on the way to the target.
Since the opponent’s hands are so close to you, if there is no preliminary movement, the hands can move and strike you before you have a chance to react. Magicians make a living from the fact that the hand is faster than the eye. Actually, the hand is not faster than the eye; what really happens is that the hand is faster than the opponent can see, analyze, decide, and react to the hand’s movement. Therefore, it is a waste of time, and dangerous, to watch an opponent’s hands for an indication of a hand attack.