2 Chronicles 20:22
And when they began to sing and to praise, the LORD set ambushments against the children of Ammon, Moab, and mount Seir, which were come against Judah; and they were smitten. And when they began to sing and to praise, the LORD set ambushments against the children of Ammon, Moab, and mount Seir, which were come against Judah; and they were smitten.
Judah under Jehoshaphat was attacked by Ammon, Moab, and Mount Seir, and in dependence on God and His prophets he consulted the people and placed singers with instruments ahead of the army to praise the beauty of holiness and His enduring mercy. The singers were set in front to declare that the mercy of the Lord endures forever, praising God for the promised victory before the battle was fought. The moment they began to sing and to praise, the Lord Himself intervened and set ambushments against the invaders so that they were smitten, not by Judah's strength.
The ambushed forces turned against one another until they were destroyed, so that when Judah looked from the watchtower all were dead bodies and none had escaped. The defeat is also that fear seized the enemies so that they fled, for as soon as praise began they saw the whole army of heaven before them and were afraid of being destroyed. Heaven has lost none of its angels and is just as ready to come to the help of God's people now as in the days of ancient Israel. Four days later the army returned to Jerusalem laden with the enemies' spoil, singing praise for the victory won.
The verse means the battle is not man's but God's, so deliverance comes through dependence and faith expressed in praise in advance. Believing in the Lord establishes His people, while believing His prophets brings prosperity. Those in peril, grief, discouragement, and trial should therefore keep their eyes on God, stand still in faith, and let Him lead and save rather than spending probationary time weeping in sackcloth or trusting gloomy feelings. They should meet trial with more music and praise and less groaning, putting faith into work, refusing discouraging speech, and refusing doleful recitations of discouragement.
They are to trust God as helper and strength and vanguard and rearguard, leaning on His almighty arm with a sympathetic intercessor pleading for them, and knowing trial comes because it is needed, for such faith pleases God and gives triumph and victory. The same praising now revives hope and courage and faith, strengthens those standing in defense of the truth, and gains many more victories. Believers should therefore keep praising, pray as never before, and hold regular praise gatherings together.
Singing and shouting to God's glory drives off the enemy, beats him back, vanquishes temptation, and brings victory over Satan and the powers of darkness that bind God's children. With darkness rising and Satan working in great power knowing his time is short, God's people must constantly rise and keep the ascendancy by increasing in power and strength and growing in grace and knowledge of the truth, or be overcome. There must be more glorifying of God and childlike simplicity, and the victory must be gained together unitedly as one instead of dragging down like weights anyone attempting to rise.