2 Chronicles 20:19
And the Levites, of the children of the Kohathites, and of the children of the Korhites, stood up to praise the LORD God of Israel with a loud voice on high. And the Levites, of the children of the Kohathites, and of the children of the Korhites, stood up to praise the LORD God of Israel with a loud voice on high.
The setting was encampment of enemies against Judah when Judah had no might against the great multitude coming against it and no knowledge of what to do except to keep its eyes upon God. Probationary time is too precious to spend in weeping and sitting in sackcloth, for the future is in the hands of Him who created the earth and He will lead all who will be led.
As Judah went out to face its enemies, the Levites of the Kohathites and Korhites stood up to praise the Lord God of Israel with a loud voice on high, while Judah and Jerusalem bowed and worshiped before Him. Their praise was a response to God's promise of deliverance, exalting Him for the promised victory, and it was offered in belief in the Lord as the way to be established. Singers were appointed to go before the army praising the beauty of holiness and affirming that His mercy endures forever.
Singing praise in the face of battle was an unusual response, and it expressed trust in God. Such praise strengthens hope and courage and faith. The battle is not man's but God's, so there is no need to fight but to take a stand, stand still, and see the salvation of the Lord. When praise begins, God sets ambushes and strikes the enemy. The lesson for those with no strength is to place dependence upon God and praise Him, and He will bring deliverance.