During the 6 Day War, a young paratrooper was getting himself ready before jumping into the warzone.
In preparation, he removed his grenades from the storage box in his knapsack, clipped them to his belt and transferred his tallis / tefillin and siddur into the storage box, feeling they would be better protected than just loose on the knapsack.
During his firefight, he was suddenly thrown off his feet, and knew he had been hit by a sniper shot. For some reason, he felt no pain, so he kept fighting.
Later in the day, he checked his knapsack and saw that the bullet that had thrown him earlier, has penetrated his storage box (the siddur took the hit)