Isaiah 27:13

That day will prove to be the greatest Day of Atonement of all time (cf. Isaiah 27:9). A trumpet blast will summon all the redeemed from distant parts of the earth, not just Jews from Palestine (cf. Zechariah 14:9; Matthew 24:31). They, too, will come to Jerusalem and enter the millennial kingdom (cf. Isaiah 19:24-25). Amillennialists typically interpret this gathering as a reference to the conversion of Gentiles to Jesus Christ (cf. Ephesians 1:10). [Note: See Young, 2:252.] Isaiah used Assyria and Egypt here as he used Edom earlier (cf. Isaiah 25:10), namely, as representative in his time of those areas of the world in the future.

"These verses provide a fitting climax to chs. 24-27 with their emphasis upon God’s sovereignty over the nations and his intention to restore his people from the nations. In this respect this is the second of three such passages. The others are Isaiah 11:12-16 and Isaiah 35:1-10. Each of these occurs at the end of a major segment. This fact suggests something about the structure of the book. . . . chs. 7-12 make the point that if you trust in the nations, the nations will destroy you. Nonetheless, God will not leave his people in destruction; he intends to deliver them from the nations. But this raises the immediate question: Can he deliver them from the nations? Chs. 13-27 answer that question with a resounding affirmative. They do so first in a particularizing way, showing that all nations, including Israel, are under God’s judgment (chs. 13-23). Then chs. 24-27 make the same point in a more generalized way, asserting that God is the main actor in the drama of human history. These things being so, God can deliver his people, and the promise is reaffirmed in these two closing verses." [Note: Oswalt, p. 500.]

"Chapters 1-12 reveal God’s saving purpose for Judah and Israel. Chapters 13-27 reveal his saving purpose for the whole world." [Note: Ortlund, p. 144.]