... The Philistine, Goliath...
His height was six cubits and a span.
He had a bronze helmet on his head and wore a coat of scale armor of bronze...
On his legs he wore bronze greaves, and a bronze javelin was slung on his back...

David took his staff in his hand, chose five smooth stones from the stream, put them in the pouch of his shepherd’s bag and, with his sling in his hand, approached the Philistine.

... the Philistine, with his shield bearer in front of him, kept coming closer to David.
He looked David over and saw that he was little more than a boy... and he despised him.
He said to David, “Am I a dog, that you come at me with sticks?” And the Philistine cursed David by his gods.
“Come here,” he said, “and I’ll give your flesh to the birds and the wild animals!”

As the Philistine moved closer to attack him, David ran quickly toward the battle line to meet him.

Reaching into his bag and taking out a stone, he slung it and struck the Philistine on the forehead. The stone sank into his forehead, and he fell facedown on the ground.

So David triumphed over the Philistine with a sling and a stone; without a sword in his hand he struck down the Philistine and killed him.