45 Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a javelin: but I come to thee in the name of Jehovah of hosts, the God of the armies of Israel, whom thou hast defied. 46 This day will Jehovah deliver thee into my hand; and I will smite thee, and take thy head from off thee; and I will give the dead bodies of the host of the Philistines this day unto the birds of the heavens, and to the wild beasts of the earth; that all the earth may know that there is a God in Israel, 47 and that all this assembly may know that Jehovah saveth not with sword and spear: for the battle is Jehovah's, and he will give you into our hand.
48 And it came to pass, when the Philistine arose, and came and drew nigh to meet David, that David hastened, and ran toward the army to meet the Philistine. 49 And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead; and the stone sank into his forehead, and he fell upon his face to the earth. 50 So David prevailed over the Philistine with a sling and with a stone, and smote the Philistine, and slew him; but there was no sword in the hand of David. 51 Then David ran, and stood over the Philistine, and took his sword, and drew it out of the sheath thereof, and slew him, and cut off his head therewith. And when the Philistines saw that their champion was dead, they fled.
Matthew Henry's Commentary on 1 Samuel 17:45-51
Commentary on 1 Samuel 17:40-47
(Read 1 Samuel 17:40-47)
The security and presumption of fools destroy them. Nothing can excel the humility, faith, and piety which appear in David's words. He expressed his assured expectation of success; he gloried in his mean appearance and arms, that the victory might be ascribed to the Lord alone.
Commentary on 1 Samuel 17:48-58
(Read 1 Samuel 17:48-58)
See how frail and uncertain life is, even when a man thinks himself best fortified; how quickly, how easily, and by how small a matter, the passage may be opened for life to go out, and death to enter! Let not the strong man glory in his strength, nor the armed man in his armour. God resists the proud, and pours contempt on those who defy him and his people. No one ever hardened his heart against God and prospered. The history is recorded, that all may exert themselves for the honour of God, and the support of his cause, with bold and unshaken reliance on him. There is one conflict in which all the followers of the Lamb are, and must be engaged; one enemy, more formidable than Goliath, still challenges the armies of Israel. But "resist the devil, and he will flee from you." Go forth to battle with the faith of David, and the powers of darkness shall not stand against you. But how often is the Christian foiled through an evil heart of unbelief!