It comes all to one whether we make these verses (as some do) the song itself that is to be sung by the Gentile world or a prophecy of what God will do to make way for the singing of that song, that evangelical new song.

I.He will appear in his power and glory more than ever. So he did in the preaching of his gospel, in the divine power and energy which went along with it, and in the wonderful success it had in the pulling down of Satan's stronghold, Isa 42:13, Isa 42:14. He had long held his peace, and been still, and refrained himself, while he winked at the times of the ignorance of the Gentile world (Act 17:30), and suffered all nations to walk in their own ways (Act 14:16); but now he shall go forth as a mighty man, as a man of war, to attack the devil's kingdom and give it a fatal blow. The going forth of the gospel is thus represented, Rev 6:2. Christ, in it, went forth conquering and to conquer. The ministry of the apostles is called their warfare; and they were the soldiers of Jesus Christ. He shall stir up jealousy, shall appear more jealous than ever for the glory of his own name and against idolatry. 1. He shall cry, in the preaching of his word, cry like a travailing woman; for the ministers of Christ preached as men in earnest, and that travailed in birth again till they saw Christ formed in the souls of the people, Gal 4:19. He shall cry, yea, roar, in the gospel woes, which are more terrible than the roaring of a lion, and which must be preached along with gospel blessings to awaken a sleeping world. 2. He shall conquer by the power of his Spirit: He shall prevail against his enemies, shall prevail to make them friends, Col 1:21. Those that contradict and blaspheme his gospel, he shall prevail to put them to silence and shame. He will destroy and devour at once all the oppositions of the powers of darkness. Satan shall fall as lightning from heaven, and he that had the power of death shall be destroyed. As a type and figure of this, to make way for the redemption of the Jews out of Babylon, God will humble the pride, and break the power, of their oppressors, and will at once destroy and devour the Babylonian monarchy. In accomplishing this destruction of Babylon by the Persian army under the command of Cyrus, he will make waste mountains and hills, level the country, and dry up all their herbs. The army, as usual, shall either carry off the forage or destroy it, and by laying bridges of boats over rivers shall turn them into islands, and so drain the fens and low grounds, to make way for the march of their army, that the pools shall be dried up. Thus, when the gospel shall be preached, it shall have a free course, and that which hinders the progress of it shall be taken out of the way.

II.He will manifest his favour and grace towards those whose spirits he had stirred up to follow him, as Ezr 1:5. Those who ask the way to Zion he will show the way, and lead in it, Isa 42:16. Those who by nature were blind, and those who, being under convictions of sin and wrath are quite at a loss and know not what to do with themselves, God will lead by a way that they knew not, will show them the way to life and happiness by Jesus Christ, who is the way, and will conduct and carry them on in that way, which before they were strangers to. Thus, in the conversion of Paul, he was struck blind first, and then God revealed his Son in him, and made the scales to fall from his eyes. They are weak in knowledge, and the truths of God at first seem unintelligible; but God will make darkness light before them, and knowledge shall be easy to them. They are weak in duty, the commands of God seem impracticable, and insuperable difficulties are in the way of their obedience; but God will make crooked things straight; their way shall be plain, and the yoke easy. Those whom God brings into the right way he will guide in it. As a type of this, he will lead the Jews, when they return out of captivity, in a ready road to their own land again, and nothing shall occur to perplex or embarrass them in their journey. These are great things, and kind things, very great and very kind; but lest any should say, "They are too great, too kind, to be expected from God by such an undeserving people as that of the Jews, such an undeserving world as that of the Gentiles," he adds, These things will I do unto them, take my word for it I will, and I will not forsake them; he that begins to show this great mercy will go on to do them good.

III.He will particularly put those to confusion who adhere to idols notwithstanding the attempts made by the preaching of the gospel to turn them from idols (Isa 42:17): They shall be turned back, and greatly ashamed, that trust in graven images. The Babylonians shall when they see how the Jews, who despise their images, are owned and delivered by the God they worship without images, and the Gentiles when they see how idolatry falls before the preaching of the gospel, is scattered like darkness before the light of the sun, and melts like snow before its heat. They shall be ashamed that ever they said to these molten images, You are our gods; for how can those help their worshippers who cannot help themselves, nor save themselves from falling into contempt? In times of reformation, when many turn from iniquity, and sin, being generally deserted, becomes unfashionable, it may be hoped that those who will not otherwise be reclaimed will be wrought upon by that consideration to be ashamed of it.

I have long time holden my peace,.... For many hundred years the Lord suffered the Gentile world to walk in their own ways, to worship their idols, and took no notice of them; he winked at and overlooked their times of ignorance, and did not bring down his vengeance upon them, nor stir up all his wrath; nor indeed did he send any among them, to reprove and convince them of their errors, and threaten them with "ruin", in case of their continuance in them:

I have been still, and refrained myself; had been silent, and said nothing against them in a providential way, but curbed and kept in his wrath and displeasure at their idolatry, as a woman in travail "holds in" (y) her breath as long as she can; to which the allusion is, as appears by what follows:

now will I cry like a travailing woman; when sharp pains are upon her, and just going to be delivered; and that so loud as to be heard all over the house. This may be taken in a good sense; the ministers of the Gospel travail in birth, and Christ in them, until he is formed in the hearts of men by regenerating and converting grace, Gal 4:19 and in an ill sense; for swift and sudden destruction, which should come on his enemies, as travail on a woman with child. So the Targum,

"as pains on a woman with child, my judgment shall be revealed (or exposed) upon them.''

I will destroy and devour at once; all enemies that should oppose him in the spread of the Gospel, in the destruction of Paganism, and establishment of Christianity in the Roman empire, who are described in the next verse.

(y) "continebam me", Pagninus, Montanus; "continui me", Junius & Tremellius, Vitringa; "diu continui iram meam sicut halitum foeminae parturientis", Grotius.

long time--namely, during the desolation of Israel (Isa 32:14).

holden my peace--(Compare Psa 50:21; Hab 1:2).

cry like a travailing woman, &c.--Like a woman in parturition, who, after having restrained her breathing for a time, at last, overcome with labor pain, lets out her voice with a panting sigh; so Jehovah will give full vent to His long pent-up wrath. Translate, instead of "destroy . . . devour"; I will at once breathe hard and pant, namely, giving loose to My wrath.