At any particular instant, a moving arrow is either at rest or in motion.
If the instant is indivisible, the arrow cannot move, because if it did, the instant would immediately be divided.
But time is made up of instants.
As the arrow cannot move in any one instant, it cannot move in time.
Hence the arrow remains at rest.
This is an example of how an incorrect model of reality (time is made up of instants) leads to incorrect predictions (movement is impossible).