A shield - "A javelin," see 1 Samuel 17:6 note.

Thou comest to me with a sword - I come to thee with the name (בשם beshem) of Jehovah of hosts; the God of the armies of Israel. What Goliath expected from his arms, David expected from the ineffable name.

Then said David to the Philistine,.... In answer to the contempt he held him in, and to the threatening words he gave him:

thou comest to me with a sword, and with a spear, and with a shield; the word for "shield" is not the same with that so rendered, 1 Samuel 17:41; which his armourbearer carried before him, but with that translated a "target", which was between his shoulders, 1 Samuel 17:6; however, they were all weapons of war, either defensive or offensive:

but I come to thee in the name of the Lord of hosts, the God of the armies of Israel, whom thou hast defied; the Lord of all hosts, in heaven and in earth in general, and in particular the God of the armies of Israel; which he was at the head of, led on, protected and defended, having a kind and merciful regard unto them, and which this Philistine had defied, reproached, and blasphemed; and now David was come, by a commission from this great Jehovah, to vindicate his honour, and to avenge his people on him: he had asked for a man, and now the Lord of hosts, as the Jews (l) observe, comes forth as a man of war, for the battle was his, as in 1 Samuel 17:47; and David was his messenger, and came in his name, and was the man into whose hands he should be given.

(l) T. Bab. Sotah, fol. 42. 2.

David answered this defiance with bold, believing courage: "Thou comest to me with sword, and javelin, and lance; but I come to thee in the name of the Lord of Saboath, the God of the ranks of Israel, whom thou hast defied. This day will Jehovah deliver thee into my hand; and I shall smite thee, and cut off thine head, and give the corpse of the army of the Philistines to the birds this day ... And all the world shall learn that Israel hath a God; and this whole assembly shall discover that Jehovah bringeth deliverance (victory) not by sword and spear: for war belongeth to Jehovah, and He will give you into our hand." Whilst Goliath boasted of his strength, David founded his own assurance of victory upon the Almighty God of Israel, whom the Philistine had defied. פּגר is to be taken collectively. לישׂראל אלהים ישׁ does not mean "God is for Israel," but "Israel hath a God," so that Elohim is of course used here in a pregnant sense. This God is Jehovah; war is his, i.e., He is the Lord of war, who has both war and its results in His power.

Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a shield: but I come to thee in the name of the LORD of hosts, the God of the armies of Israel, whom thou hast defied.

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.