5:17-25 The Philistines considered not that David had the presence of God with him, which Saul had forfeited and lost. The kingdom of the Messiah, as soon as it was set up in the world, was thus attacked by the powers of darkness. The heathen raged, and the kings of the earth set themselves to oppose it; but all in vain, Ps 2:1, &c. The destruction will turn, as this did, upon Satan's own kingdom. David owns dependence on God for victory; and refers himself to the good pleasure of God, Wilt thou do it? The assurance God has given us of victory over our spiritual enemies, should encourage us in our spiritual conflicts. David waited till God moved; he stirred then, but not till then. He was trained up in dependence on God and his providence. God performed his promise, and David failed not to improve his advantages. When the kingdom of the Messiah was to be set up, the apostles, who were to beat down the devil's kingdom, must not attempt any thing till they received the promise of the Spirit; who came with a sound from heaven, as of a rushing, mighty wind, Ac 2:2.

18. valley of Rephaim—that is, "of giants," a broad and fertile plain, which descends gradually from the central mountains towards the northwest. It was the route by which they marched against Jerusalem. The "hold" to which David went down "was some fortified place where he might oppose the progress of the invaders," and where he signally defeated them.