2 Chronicles 25:6

Amaziah's army of 300,000 was smaller than Asa's 580,000 or Jehoshaphat's 1,160,000. This might explain why Amaziah wanted to hire more troops from Israel, the northern kingdom.

He hired also an hundred thousand mighty men of valour . . . for an hundred talents of silver--This sum was paid into the treasury of Jehoahaz--not given as bounty to the mercenaries who were obliged to serve at the sovereign's call; their remuneration consisting only in the booty they might obtain. It was about £50,000 sterling, being 10s. per man, including officers--a very paltry pay, compared with the bounty given for a soldier in this country. But it must be remembered that in ancient times campaigns were short and the hazards of the service comparatively small.

Here is, I. The general character of Amaziah: He did that which was right in the eyes of the Lord, worshipped the true God, kept the temple service a going, and countenanced religion in his kingdom; but he did not do it with a perfect heart (Ch2 25:2), that is, he was not a man of serious piety or devotion himself, nor had he any zeal for the exercises of religion. He was no enemy to it, but a cool and indifferent friend. Such is the character of too many in this Laodicean age: they do that which is good, but not with the heart, not with a perfect heart.
II. A necessary piece of justice which he did upon the traitors that murdered his father: he put them to death, Ch2 25:3. Though we should suppose they intended to avenge on their king the death of the prophet (as was intimated, Ch2 24:25), yet this would by no means justify their wickedness; for they were not the avengers, but presumptuously took God's work out of his hands: and therefore Amaziah did what became him in calling them to an account for it, but forbade the putting of the children to death for the parents' sin, Ch2 25:4.
III. An expedition of his against the Edomites, who, some time ago, had revolted from under the dominion of Judah, to which he attempted to reduce them. Observe,
1. The great preparation he made for this expedition. (1.) He mustered his own forces, and marshalled them (Ch2 25:5), and found Judah and Benjamin in all but 300,000 men that were fit for war, whereas, in Jehoshaphat's time, fifty or sixty years before, they were four times as many. Sin weakens a people, diminishes them, dispirits them, and lessens their number and figure. (2.) He hired auxiliary troops out of the kingdom of Israel, Ch2 25:6. Finding his own kingdom defective in men, he thought to make up the deficiency with his money, and therefore took into his pay 100,000 Israelites. If he had advised with any of his prophets before he did this, or had but considered how little any of his ancestors got by their alliances with Israel, he would not have had this to undo again. But rashness makes work for repentance.
2. The command which God sent him by a prophet to dismiss out of his service the forces of Israel, Ch2 25:7, Ch2 25:8. He would not have him call in any assistance at all: it looked like distrust of God. If he made sure of God's presence, the army he had of his own was sufficient. But particularly he must not take in their assistance: For the Lord is not with the children of Ephraim, because they are not with him, but worship the calves. This was a good reason why he should not make use of them, because he could not depend upon them to do him any service. What good could be expected from those that had not God with them, nor his blessings upon their undertakings? It is comfortable to employ those who, we have reason to hope, have an interest in heaven, and dangerous to associate with those from whom the Lord has departed. The prophet assured him that if he persisted in his resolution to take these idolatrous apostate Israelites with him, in hopes thereby to make himself strong for the battle, it was at his peril; they would prove a dead weight to his army, would sink and betray it: "God shall make thee fall before the enemy, and these Israelites will be the ruin of thy cause; for God has power to help thee without them, and to cast thee down though thou hast them with thee."
3. The objection which Amaziah made against this command, and the satisfactory answer which the prophet gave to that objection, Ch2 25:9. The king had remitted 100 talents to the men of Israel for advance-money. "Now," says he, "if I send them back, I shall lose that: But what shall we do for the 100 talents?" This is an objection men often make against their duty: they are afraid of losing by it. "Regard not that," says the prophet: "The Lord is able to give thee much more than this; and, thou mayest depend upon it, he will not see thee lose by him. What are 100 talents between thee and him? He has ways enough to make up the loss to thee; it is below thee to speak of it." Note, A firm belief of God's all-sufficiency to bear us out in our duty, and to make up all the loss and damage we sustain in his service abundantly to our advantage, will make his yoke very easy and his burden very light. What is it to trust in God, but to be willing to venture the loss of any thing for him, in confidence of the goodness of the security he gives us that we shall not lose by him, but that whatever we part with for his sake shall be made up to us in kind or kindness. When we grudge to part with any thing for God and our religion, this should satisfy us, that God is able to give us much more than this. He is just, and he is good, and he is solvent. The king lost 100 talents by his obedience; and we find just that sum given to his grandson Jotham as a present (Ch2 27:5); then the principal was repaid, and, for interest, 10,000 measures of wheat and as many of barley.
4. His obedience to the command of God, which is upon record to his honour. He would rather lose his money, disoblige his allies, and dismiss a fourth part of his army just as they were going to take the field, than offend God: He separated the army of Ephraim, to go home again, Ch2 25:10. And they went home in great anger, taking it as a great affront thus to be made fools of, and to be cashiered as men not fit to be employed, and being perhaps disappointed of the advantages they promised themselves in spoil and plunder by joining with Judah against Edom. Men are apt to resent that which touches them in their profit or reputation, though it frees them from trouble.
5. His triumphs over the Edomites, Ch2 25:11, Ch2 25:12. He left dead upon the spot, in the field of battle, 10,000 men; 10,000 more he took prisoners, and barbarously killed them all by throwing them down some steep and craggy precipice. What provocation he had to exercise this cruelty towards them we are not told; but it was certainly very severe.
6. The mischief which the disbanded soldiers of Israel did to the cities of Judah, either in their return or soon after, Ch2 25:13. They were so enraged at being sent home that, if they might not go to share with Judah in the spoil of Edom, they would make a prey of Judah. Several cities that lay upon the borders they plundered, killing 3000 men that made resistance. But why should God suffer this to be done? Was it not in obedience to him that they were sent home, and yet shall the country thus suffer by it? Surely God's way is in the sea! Did not the prophet say that God was not with the children of Ephraim, and yet they are suffered to prevail against Judah? Doubtless God intended hereby to chastise those cities of Judah for their idolatries, which were found most in those parts that lay next to Israel. The men of Israel had corrupted them, and now they were made a plague to them. Satan both tempts and torments.

Gathered Judah together - He purposed to avenge himself of the Syrians, but wished to know his military strength before he came to a rupture.

He hired also one hundred thousand mighty men of valour out of Israel,.... The ten tribes, judging his own army not sufficient for his expedition against the Edomites he was meditating:

for one hundred talents of silver; which amounted to 35,300 pounds sterling, and according to Beckius (e) were about five florins and a half to each soldier.

(e) Not. in Targum in loc.

Out of Israel; out of the kingdom of the ten tribes.