This explains the foregoing promise of the deliverance of Jerusalem; she shall be fitted for deliverance, and then it shall be wrought for her; for in that method God delivers. I. Jerusalem shall be reformed, and so she shall be delivered from her enemies within her walls, Isa 31:6, Isa 31:7. Here is, 1. A gracious call to repentance. This was the Lord's voice crying in the city, the voice of the rod, the voice of the sword, and the voice of the prophets interpreting the judgment: "Turn you, O turn you now, from your evil ways, unto God, return to your allegiance to him from whom the children of Israel have deeply revolted, from whom you, O children of Israel! have revolted." He reminds them of their birth and parentage, that they were children of Israel, and therefore under the highest obligations imaginable to the God of Israel, as an aggravation of their revolt from him and as an encouragement to them to return to him. "They have been backsliding children, yet children; therefore let them return, and their backslidings shall be healed. They have deeply revolted, with great address as they supposed (the revolters are profound, Hos 5:2); but the issue will prove that they have revolted dangerously. The stain of their sins has gone deeply into their nature, not to be easily got out, like the blackness of the Ethiopian. They have deeply corrupted themselves (Hos 9:9); they have sunk deep into misery, and cannot easily recover themselves; therefore you have need to hasten your return to God." 2. A gracious promise of the good success of this call (Isa 31:7): In that day every man shall cast away his idols, in obedience to Hezekiah's orders, which, till they were alarmed by the Assyrian invasion, many refused to do. That is a happy fright which frightens us from our sins. (1.) It shall be a general reformation: every man shall cast away his own idols, shall begin with them before he undertakes to demolish other people's idols, which there will be no need of when every man reforms himself. (2.) It shall be a thorough reformation; for they shall part with their idolatry, their beloved sin, with their idols of silver and gold, their idols that they are most fond of. Many make an idol of their silver and gold, and by the love of that idol are drawn to revolt from God; but those that turn to God cast that away out of their hearts and will be ready to part with it when God calls. (3.) It shall be a reformation upon a right principle, a principle of piety, not of politics. They shall cast away their idols, because they have been unto them for a sin, an occasion of sin; therefore they will have nothing to do with them, though they had been the work of their own hands, and upon that account they had a particular fondness for them. Sin is the work of our own hands, but in working it we have been working our own ruin, and therefore we must cast it away; and those are strangely wedded to it who will not be prevailed upon to cast it away when they see that otherwise they themselves will be castaways. Some make this to be only a prediction that those who trust in idols, when they find they stand them in no stead, will cast them away in indignation. But it agrees so exactly with Isa 30:22 that I rather take it as a promise of a sincere reformation. II. Jerusalem's besiegers shall be routed, and so she shall be delivered from the enemies about her walls. The former makes way for this. If a people return to God, they may leave it to him to plead their cause against their enemies. When they have cast away their idols, then shall the Assyrian fall, Isa 31:8, Isa 31:9. 1. The army of the Assyrians shall be laid dead upon the spot by the sword, not of a mighty man, nor of a mean man, not of any man at all, either Israelite or Egyptian, not forcibly by the sword of a mighty man nor surreptitiously by the sword of a mean man, but by the sword of an angel, who strikes more strongly than a mighty man and yet more secretly than a mean man, by the sword of the Lord, and his power and wrath in the hand of the angel. Thus the young men of the army shall melt, and be discomfited, and become tributaries to death. When God has work to do against the enemies of his church we expect it must be done by mighty men and mean men, officers and common soldiers; whereas God can, if he please, do it without either. He needs not armies of men who has legions of angels at command, Mat 26:53. 2. The king of Assyria shall flee for the same, shall flee from that invisible sword, hoping to get out of the reach of it; and he shall make the best of his way to his own dominions, shall pass over to some strong-hold of his own, for fear lest the Jews should pursue him now that his army was routed. Sennacherib had been very confident that he should make himself master of Jerusalem, and in the most insolent manner had set both God and Hezekiah at defiance; yet now he is made to tremble for fear of both. God can strike a terror into the proudest of men, and make the stoutest heart to tremble. See Job 18:11; Job 20:24. His princes that accompany him shall be afraid of the ensign, shall be in a continual fright at the remembrance of the ensign in the air, which perhaps the destroying angel displayed before he gave the fatal bow. Or they shall be afraid of every ensign they see, suspecting it is a party of the Jews pursuing them. The banner that God displays for the encouragement of his people (Psa 60:4) will be a terror to his and their enemies. Thus he cuts off the spirit of princes and is terrible to the kings of the earth. But who will do this? It is the Lord, whose fire is in Zion and his furnace in Jerusalem. (1.) Whose residence is there, and who there keeps house, as a man does where his fire and his oven are. It is the city of the great King, and let not the Assyrians think to turn him out of the possession of his own house. (2.) Who is there a consuming fire to all his enemies and will make them as a fiery oven in the day of his wrath, Psa 21:9. He is himself a wall of fire round about Jerusalem, so that whoever assaults her does so at his peril, Zac 2:5; Rev 11:5. (3.) Who has his altar there, on which the holy fire is continually kept burning and sacrifices are daily offered to his honour, and with which he is well pleased; and therefore he will defend this city, especially having an eye to the great sacrifice which was there also to be offered, of which all the sacrifices were types. If we keep up the fire of holy love and devotion in our hearts and houses, we may depend upon God to be a protection to us and them.