45 Then David said to the Philistine, "You come to me with a sword, with a spear, and with a javelin. But I come to you in the name of the Lord of hosts, the God of the armies of Israel, whom you have defied. 46 This day the Lord will deliver you into my hand, and I will strike you and take your head from you. And this day I will give the carcasses of the camp of the Philistines to the birds of the air and the wild beasts of the earth, that all the earth may know that there is a God in Israel.

Matthew Henry's Commentary on 1 Samuel 17:45-46

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.