In the name of the Lord of hosts, i.e. by a commission from him, with confidence in him, and assurance of his help, and for the vindication of his honour. Whom thou hast defied, in defying that army and people whereof he is the Lord and Protector.
Related Commentaries of 1 Samuel 17:45
1 Samuel 17:45
45 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.