It is generally supposed that this chapter is a continuation of the subject of the foregoing (Lowth). The general design is to reprove the hypocritical portion of the nation, and to comfort the pious with the assurance of the favor of God, the accession of the Gentile world, and the destruction of the foes of the church. The Jews valued themselves much upon the pomp of their temple-worship and the splendor of their ritual; they supposed that that was to he perpetual; and they assumed great merit to themselves for the regular servives of their religion. Before the captivity in Babylon they were prone to fall into idolatry; afterward they were kept from it, and to the present time they have not been guilty of it - so effectual was that heavy judgment in correcting this national propensity. But after their captivity their national proneness to sin assumed another form. That love of form and strict ceremony; that dependence on mere rites and the external duties of religion; that heartless and pompous system of worship commenced, which ultimately terminated in Pharisaic pride, and which was scarcely less an object of abhorrence to God than gross idolatry. To that state of things the prophet probably looked forward; and his object in this chapter was to reprove that reliance on the mere forms of external worship, and the pride in their temple and its service which he saw would succeed the return from the exile in Babylon.
It is generally agreed that the reference here is to the state of things which would follow the return from Babylon. Lowth supposes that it refers to the time when Herod would be rebuilding the temple in the most magnificent manner, and when, notwithstanding the heavy judgment of God was hanging over their heads, the nation was formal in its worship, and proud and self-confident, as if it was the favorite of God. Vitringa supposes that it refers to the time of the introduction of the new economy, or the beginning of the times of the Messiah.
That it refers to times succeeding the captivity at Babylon, and is designed to be at once a prophetic description and a reproof of the sins which would prevail after their return, is apparent from the whole structure of the chapter, and particularly from the following considerations:
1. There is no one description, as in the former chapters, of the land as desolate, or the city of Jerusalem and the temple in ruins (see Isaiah 64:10-11).
2. There is no charge against them for being idolatrous, as there had been in the previous chapters (see especially Isaiah 65:3-4, Isaiah 65:11). The sin that is specified here is of a wholly different kind.
3. It is evidently addressed to them when they were either rebuilding the temple, or when they greatly prided themselves on its service (see Isaiah 66:1).
4. It is addressed to them when they were engaged in offering sacrifice with great formality, and with great reliance on the mere external services of religion; when sacrifice had degenerated into mere form, and when the spirit with which it was done was as abominable in the sight of God as the most odious of all crimes.
From these considerations, it seems to me that the chapter is designed to refer to a state of things that would succeed the return from the exile at Babylon, and be a general description of the spirit with which they would then engage in the worship of God. They would indeed rebuild the temple according to the promise; but they would manifest a spirit in regard to the temple which required the severe reproof of Yahweh. They would again offer sacrifice in the place where their fathers had done it; but though they would be effectually cured of their idolatrous tendencies, yet they would evince a spirit that was as hateful to God as the worst form of idolatry, or the most heinous crimes. A large portion, therefore, of the nation would still be the object of the divine abhorrence, and be subjected to punishment; but the truly pious would be preserved, and their number would be increased by the accession of the Gentile world.
As an additional consideration to show the correctness of this view of the time to which the chapter refers, we may remark, that a large part of the prophecies of Isaiah are employed in predicting the certain return from the exile, the re-establishment of religion in their own land, and the resumption of the worship of God there. It was natural, therefore, that the spirit of inspiration should glance at the character of the natron subsequent to the return, and that the prophet should give, in the conclusion of his book, a summary graphic description of what would occur in future times. This I take to be the design of the closing chapter of the prophecies of Isaiah. He states in general the character of the Jewish people after the return from the exile; condemns the sins with which they would then be chargeable; comforts the portion of the nation that would be disposed in sincerity to serve God; predicts the rapid and glorious increase of the church; declares that the enemies of God would be cut off; affirms that all the world would yet come at stated seasons to worship before God; and closes the whole book by saying that the people of God would go forth and see all their enemies slain. This general view may be more distinctly seen by the following analysis of the chapter:
I. Yahweh says that heaven was his throne, and the earth his footstool, and that no house which they could build for him would adequately express his glory; no external worship would suitably declare his majesty. He preferred the homage of an humble heart to the most magnificent external worship; the tribute of a sincere offering to the most costly outward devotion Isaiah 66:1-2.
II. He declares his sense of the evil of mere external worship, and threatens punishment to the hypocrites who should engage in this manner in his service Isaiah 66:3-4. In these verses it is implied that in the service of the temple after the return from the exile, there would be a spirit evinced in their public worship that would be as hateful to God as would lie murder or idolatry, or as would be the cutting off a dog's neck or the sacrifice of swine; that is, that the spirit of hypocrisy, self-righteousness, and pride, would be supremely odious in his sight. They were not therefore to infer that because they would be restored from the exile, therefore their worship would be pure and acceptable to God. The fact would be that it would become so utterly abominable in his sight that he would cut them off and bring all their fears upon them; that is, he would severely punish them.
III. Yet even then there would be a portion of the people that would hear the word of the Lord, and to whom he would send comfort and deliverance. He therefore promises to his true church great extension, and especially the accession of the Gentiles Isaiah 66:5-14.
1. A part of the nation would cast out, and persecute the other, under pretence of promoting the glory of God and doing his will Isaiah 66:5. Yet Yahweh would appear for the joy of the persecuted portion, and the persecutors would be confounded.
2. A sound is heard as of great agitation in the city; a voice indicating great and important revolutions Isaiah 66:6. This voice is designed to produce consolation to his people; dismay to his foes.
3. A promise is given of the great and sudden enlargement of Zion - an increase when conversions would be as sudden as if a child were born without the ordinary delay and pain of parturition; as great as if a nation were born in a day Isaiah 66:7-9.
4. All that love Zion are called on to rejoice with her, for the Gentile nations would come like a flowing stream, and the church would be comforted, as when a mother comforteth her child Isaiah 66:10-14.
IV. God would punish his foes. He would devote idolaters to destruction Isaiah 66:15-17.
V. He would send the message of salvation to those who were in distant parts of the world Isaiah 66:19-21.
VI. At that time, the worship of God would everywhere be regularly and publicly celebrated. From one new moon to another: and from one Sabbath to another, all flesh would come and worship before God Isaiah 66:23.
VII. The friends of God would be permitted to see the final and interminable ruin of all the transgressors against the Most High Isaiah 66:24. Their destruction would be complete; their worm would not die, and their fire would not be quenched and the whole scene of the work of redemption would be wound up in the complete and eternal salvation of all the true people of God, and in the complete and eternal ruin of all his foes. With this solemn truth - a truth relating to the final retribution of mankind, the prophecies of Isaiah appropriately close. Where more properly could be the winding up of the series of visions in this wonderful book, than in a view of the complete destruction of the enemies of God; how more sublimely than by representing the whole redeemed church as going forth together to look upon their destruction, as victors go forth to look upon a mighty army of foes slain and unburied on the battlefield?

This chapter treats of the same subject with the foregoing. God, by his prophet, tells the Jews, who valued themselves much on their temple and pompous worship, that the Most High dwelleth not in temples made with hands; and that no outward rites of worship, while the worshippers are idolatrous and impure, can please him who looketh at the heart, Isaiah 66:1-3. This leads to a threatening of vengeance for their guilt, alluding to their making void the law of God by their abominable traditions, their rejection of Christ, persecution of his followers, and consequent destruction by the Romans. But as the Jewish ritual and people shadow forth the system of Christianity and its professors; so, in the prophetical writings, the idolatries of the Jews are frequently put for the idolatries afterwards practiced by those bearing the Christian name. Consequently, if we would have the plenitude of meaning in this section of prophecy, which the very content requires, we must look through the type into the antitype, viz., the very gross idolatries practiced by the members of Antichrist, the pompous heap of human intentions and traditions with which they have encumbered the Christian system, their most dreadful persecution of Christ's spiritual and true worshippers, and the awful judgments which shall overtake them in the great and terrible day of the Lord, Isaiah 66:4-6. The mighty and sudden increase of the Church of Jesus Christ at the period of Antichrist's fall represented by the very strong figure of Sion being delivered of a man-child before the time of her travail, the meaning of which symbol the prophet immediately subjoins in a series of interrogations for the sake of greater force and emphasis, Isaiah 66:7-9. Wonderful prosperity and unspeakable blessedness of the world when the posterity of Jacob, with the fullness of the Gentiles, shall be assembled to Messiah's standard, Isaiah 66:10-14. All the wicked of the earth shall be gathered together to the battle of that great day of God Almighty, and the slain of Jehovah shall be many, Isaiah 66:15-18. Manner of the future restoration of the Israelites from their several dispersions throughout the habitable globe, Isaiah 66:19-21. Perpetuity of this new economy of grace to the house of Israel, Isaiah 66:22. Righteousness shall be universally diffused in the earth; and the memory of those who have transgressed against the Lord shall be had in continual abhorrence, Isaiah 66:23, Isaiah 66:24. Thus this great prophet, after tracing the principal events of time, seems at length to have terminated his views in eternity, where all revolutions cease, where the blessedness of the righteous shall be unchangeable as the new heavens, and the misery of the wicked as the fire that shall not be quenched.
This chapter is a continuation of the subject of the foregoing. The Jews valued themselves much upon their temple, and the pompous system of services performed in it, which they supposed were to be of perpetual duration; and they assumed great confidence and merit to themselves for their strict observance of all the externals of their religion. And at the very time when the judgments denounced in Isaiah 65:6 and Isaiah 65:12 of the preceding chapter were hanging over their heads, they were rebuilding, by Herod's munificence, the temple in a most magnificent manner. God admonishes them, that "the Most High dwelleth not in temples made with hands;" and that a mere external worship, how diligently soever attended, when accompanied with wicked and idolatrous practices in the worshippers, would never be accepted by him. This their hypocrisy is set forth in strong colors, which brings the prophet again to the subject of the former chapter; and he pursues it in a different manner, with more express declaration of the new economy, and of the flourishing state of the Church under it. The increase of the Church is to be sudden and astonishing. They that escape of the Jews, that is, that become converts to the Christian faith, are to be employed in the Divine mission to the Gentiles, and are to act as priests in presenting the Gentiles as an offering to God; see Romans 15:16. And both, now collected into one body, shall be witnesses of the final perdition of the obstinate and irreclaimable.
These two chapters manifestly relate to the calling of the Gentiles, the establishment of the Christian dispensation, and the reprobation of the apostate Jews, and their destruction executed by the Romans. - L.

INTRODUCTION TO ISAIAH 66
This chapter treats of the same things as the former, the rejection of the unbelieving Jews, and the regard had to them that did believe; the conversion of that people in the latter day; the calling of the Gentiles, and the happy state of the church in the last times. The causes of the rejection of the Jews were their unworthy notions of God, as if he was confined to the temple of Jerusalem, and to be pleased with external sacrifices, now both at an end under the Gospel dispensation; a better sacrifice being offered, and a more spiritual worship set up everywhere; which notions are considered, Isaiah 66:1, and because they were set upon their ways and works, and rejected the Gospel of Christ, they are threatened with ruin, Isaiah 66:3 and the disciples of Christ, whom they excommunicated and persecuted, have a promise of divine appearance for them, while vengeance shall be taken on their enemies, their city and temple, Isaiah 66:5, nevertheless, in the latter day, there will be a large and sudden conversion of this nation of the Jews, which is signified by the birth of them, which will be matter of great joy to all the true lovers of the interest of Christ, Isaiah 66:7 and what will add to the prosperity, joy, and comfort of the church of Christ at this time, will be the bringing in of the fulness of the Gentiles, Isaiah 66:12 at which time the vials of God's wrath will be poured out upon antichrist and his followers, Isaiah 66:15 and the chapter is concluded with a fresh account of large conversions of men of all nations, and of the union of Jews and Gentiles in one church state, which shall long remain, and be undisturbed by enemies, who will be all slain, and their carcasses looked upon with contempt, Isaiah 66:18.

(Isaiah 66:1-4) God looks at the heart, and vengeance is threatened for guilt.
(Isaiah 66:5-14) The increase of the church, when Jew and Gentile shall be gathered to the Redeemer.
(Isaiah 66:15-24) Every enemy of the church shall be destroyed, and the final ruin of ungodly men shall be seen.