David killed Goliath with a sling and a stone; there was no sword in David’s hand. [1 Samuel 17:50)]

Then David ran and stood over Goliath; he grasped his sword, drew it out of its sheath, and killed him; then he cut off his head with it. [1 Samuel 17:51 ]

Killed again? And where did the sword come from? Oops!