20:1-13 In all dangers, public or personal, our first business should be to seek help from God. Hence the advantage of days for national fasting and prayer. From the first to the last of our seeking the Lord, we must approach him with humiliation for our sins, trusting only in his mercy and power. Jehoshaphat acknowledges the sovereign dominion of the Divine Providence. Lord, exert it on our behalf. Whom should we seek to, whom should we trust to for relief, but the God we have chosen and served. Those that use what they have for God, may comfortably hope he will secure it to them. Every true believer is a son of Abraham, a friend of God; with such the everlasting covenant is established, to such every promise belongs. We are assured of God's love, by his dwelling in human nature in the person of the Saviour. Jehoshaphat mentions the temple, as a token of God's favourable presence. He pleads the injustice of his enemies. We may well appeal to God against those that render us evil for good. Though he had a great army, he said, We have no might without thee; we rely upon thee.
3, 4. Jehoshaphat … proclaimed a fast throughout all Judah—Alarmed by the intelligence and conscious of his total inability to repel this host of invaders, Jehoshaphat felt his only refuge was at the horns of the altar. He resolved to employ the aid of his God, and, in conformity with this resolution, he summoned all his subjects to observe a solemn fast at the sanctuary. It was customary with the Hebrew kings to proclaim fasts in perilous circumstances, either in a city, a district, or throughout the entire kingdom, according to the greatness of the emergency. On this occasion, it was a universal fast, which extended to infants (2Ch 20:13; see also Joe 2:15, 16; Jon 3:7).