III. The summons given them is effectual, their obedience ready, and they make a very formidable appearance: A banner is lifted up upon the high mountain, v. 2. God's standard is set up, a flag of defiance hung out against Babylon. It is erected on high, where all may see it; whoever will may come and enlist themselves under it, and they shall be taken immediately into God's pay. Those that beat up for volunteers must exalt the voice in making proclamation, to encourage soldiers to come in; they must shake the hand, to beckon those at a distance and to animate those that have enlisted themselves. And they shall not do this in vain; God has commanded and called those whom he designs to make use of (v. 3) and power goes along with his calls and commands, which cannot be resisted. He that makes men able to serve him can, when he pleases, make them willing too. It is the Lord of hosts that musters the host of the battle, v. 4. He raises them, brings them together, puts them in order, reviews them, has an exact account of them in his muster-roll, sees that they be all in their respective posts, and gives them their necessary orders. Note, All the hosts of war are under the command of the Lord of hosts; and that which makes them truly formidable is that, when they come against Babylon, the Lord comes, and brings them with him as the weapons of his indignation, v. 5. Note, Great princes and armies are but tools in God's hand, weapons that he is pleased to make use of in doing his work, and it is his wrath that arms them and gives them success.