“I cannot walk in these,” David said to Saul. “I am not accustomed to them.” So David took them off. And David took his staff in his hand, selected five smooth stones from the brook, and put them in the pouch of his shepherd’s bag. And with his sling in hand, he approached the Philistine.
David takes his staff, chooses five smooth stones from the brook, puts them in his shepherd's bag, and approaches the Philistine with his sling.
It sends David into battle with familiar tools rather than royal weapons.
38Then Saul clothed David in his own tunic, put a bronze helmet on his head, and dressed him in armor. 39David strapped his sword over the tunic and tried to walk, but he was not accustomed to them. 40“I cannot walk in these,” David said to Saul. “I am not accustomed to them.” So David took them off. And David took his staff in his hand, selected five smooth stones from the brook, and put them in the pouch of his shepherd’s bag. And with his sling in hand, he approached the Philistine. 41Now the Philistine came closer and closer to David, with his shield-bearer before him. 42When the Philistine looked and saw David, he despised him because he was just a boy, ruddy and handsome. 43“Am I a dog,” he said to David, “that you come at me with sticks?” And the Philistine cursed David by his gods. 44“Come here,” he called to David, “and I will give your flesh to the birds of the air and the beasts of the field!” 45But David said to the Philistine, “You come against me with sword and spear and javelin, but I come against you in the name of the LORD of Hosts, the God of the armies of Israel, whom you have defied. 46This day the LORD will deliver you into my hand. This day I will strike you down, cut off your head, and give the carcasses of the Philistine army to the birds of the air and the creatures of the earth. Then the whole world will know that there is a God in Israel. 47And all those assembled here will know that it is not by sword or spear that the LORD saves; for the battle is the LORD’s, and He will give all of you into our hands.” 48As the Philistine started forward to attack him, David ran quickly toward the battle line to meet him. 49Then David reached into his bag, took out a stone, and slung it, striking the Philistine on the forehead. The stone sank into his forehead, and he fell facedown on the ground. 50Thus David prevailed over the Philistine with a sling and a stone; without a sword in his hand he struck down the Philistine and killed him. 51David ran and stood over him. He grabbed the Philistine’s sword and pulled it from its sheath and killed him, and he cut off his head with the sword. 52When the Philistines saw that their hero was dead, they turned and ran. Then the men of Israel and Judah charged forward with a shout and pursued the Philistines to the entrance of Gath and to the gates of Ekron. And the bodies of the Philistines were strewn along the Shaaraim road to Gath and Ekron. 53When the Israelites returned from their pursuit of the Philistines, they plundered their camps. 54David took the head of the Philistine and brought it to Jerusalem, and he put Goliath’s weapons in his own tent. 55As Saul had watched David going out to confront the Philistine, he said to Abner the commander of the army, “Abner, whose son is this young man?” 56“Find out whose son this young man is!” said the king. 57So when David returned from killing the Philistine, still holding his head in his hand, Abner took him and brought him before Saul. 58“Whose son are you, young man?” asked Saul.