45 And David said to the Philistine, Thou comest to me with sword, and with spear, and with 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 up into my hand; and I will smite thee, and take thy head from thee; and I will give the carcases of the camp of the Philistines this day to the fowl of the heavens and to the wild beasts of the earth. And all the earth shall know that Israel has a God; 47 and all this congregation shall know that Jehovah saves not with sword and spear; for the battle is Jehovah's, and he will give you into our hands.
Matthew Henry's Commentary on 1 Samuel 17:45-47
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.