And when they began. — Literally, And at the. time when they began with shouting and praise. (Comp. Deuteronomy 16:9, to begin with.) They had now reached the neighbourhood of the enemy; and their joyful pæan was the signal for a Divine interposition. (Comp. Joshua 6:16; Joshua 6:20, and Psalms 46:6.)
The Lord set ambushments. — Jehovah placed liers in wait (Judges 9:25). (nâthan here is equivalent in meaning to sâm there.)
Come against. — Come into, i.e., invade (2 Chronicles 20:10).
They were smitten. — Right, according to the ordinary usage. (See 1 Chronicles 19:16; 1 Chronicles 19:19, “put to the worse.”) This statement anticipates what follows. The ancient translators felt a difficulty here, as is evident from their versions. Thus the LXX. has, “The Lord made the sons of Ammon to war upon Moab and Mount Seir, who came out against Judah; and they were routed.” The Vulg., “The Lord turned their ambushment against themselves, viz., that of the sons of Amnion and Moab and Mount Seir, who had gone forth to fight against Judah, and they were smitten.”
The Syriac (and Arabic) travesty 2 Chronicles 20:21 and the first clause of 2 Chronicles 20:22 thus: “And he stood in the middle of the people, and said, Come, let us give thanks unto the Lord, and let us laud the splendour of his holiness, when he goeth out before our hosts, and maketh war for us with our foes: and be saying, Give thanks unto the Lord, for he is good, and his goodness endureth for ever. The hills began praising, and the mountains began rejoicing.”They then continue as in 2 Chronicles 20:24, omitting “The Lord set ambushments... they were smitten.”
The self-destruction of the allied hordes was undoubtedly providential, but it need not have been miraculous. How was it brought about? The answer depends on the meaning of the term “liers in wait.” Were angels meant, as some have thought (Ewald’s böser Geister), a more appropriate and less ambiguous term would have been employed to express their agency. Nor is it likely that a Judean ambuscade is thus obscurely mentioned without any further reference or explanation: indeed it is evident from 2 Chronicles 20:15; 2 Chronicles 20:17; 2 Chronicles 20:24, that the part of the Judeans was that of mere spectators of an accomplished fact. Nor, finally, must we suppose that “the waylaying was done by a section of the confederates themselves, probably certain of the Maonites.”
The truth appears to be that some portion of the unwieldy and straggling host was suddenly attacked by a lurking band of Bedawi freebooters. In the providence of God the partial confusion which thus originated speedily became a universal panic. The Ammonites and Moabites instantly suspected their less civilised allies, the Maonites, of treachery, and fell upon them in a frenzy of revenge; after which, maddened by slaughter and mutual suspicion, and the memory of ancient feuds, they turned their reeking swords against each other, and the strife only ended with the self-annihilation of the allies. The occurrence is thus to some extent parallel with the self-destruction of the Midianite hordes, when thrown into confusion by the stratagem of Gideon (Judges 7:22).
The marvellous result, marvellously predicted, was brought to pass by a perfectly natural sequence of events, just as was Elisha’s prophecy of plenty to famine-stricken Samaria, though at the time when it was uttered fulfilment seemed impossible, unless the Lord were to “make windows in heaven,” and pour down supplies from thence by a visible miracle. In neither case was the course of events foreseen by the prophet, but only their issue. (See 2 Kings 7)