In God’s judgment, all that is proud and lofty, that is, all that attempts to put itself in the place of God, will be humbled. God alone will be exalted.
Here is another side of the “day of the Lord” theme. Most often in the eighth century B.C.E., the The Day of the Lord, in prophetic writing, is the day of judgment when God will intervene directly in world affairs. As described in Zephaniah, for instance, God will sweep everything away. In Matthew's gospel God is described as gathering the elect on the day... More was thought to be the time of God’s great defeat of the enemies of Israel. Babylon is summoned by Isaiah, son of Amoz, who prophesied in Jerusalem, is included among the prophets of the eighth century B.C.E. (along with Amos, Hosea, and Micah)--preachers who boldly proclaimed God's word of judgment against the economic, social, and religious disorders of their time. More to “Wail, for the day of the LORD is near; it will come like destruction from the Almighty!” (13:6). Israel, of course, would rejoice (12:1-2). Sometimes that day was seen to be ushered in by historical events; sometimes it seems to look beyond history as we know it.
But prophets like Isaiah and Prophet to the northern kingdom who condemned Israel's oppression of the poor, calling for justice to "roll down like waters." More also gave the notion a new twist: now, as in this text, the Lord’s Day could be directed against Judah was the name of Jacob's fourth son and one of the 12 tribes. More (or Israel, in other texts) as well as against the nations. Amos makes it most clear: “Alas for you who desire the day of the LORD! Why do you want the day of the LORD? It is darkness, not light” (Amos 5:18).
This is a very significant move in biblical theology, for it marks a striking shift away from the general religious notion that obviously “our god” is on “our side” and that the superiority of a god is shown by decisive victories against the “enemies.” Such a view can and does lead to dangerous notions of pride. But, as Isaiah points out in this text, such pride itself is perhaps the greatest impediment to fidelity and obedience to God. The danger to life and Salvation can mean saved from something (deliverance) or for something (redemption). Paul preached that salvation comes through the death of Christ on the cross which redeemed sinners from death and for a grace-filled life. More is so great that God must proclaim a “day” in which all such pride and haughtiness will be humbled. Only God will be exalted–that is, worshiped and lifted up as God. The text seems to understand with Genesis 3 that the attempt to “be like God” is the most basic human sin.
This recognition of the chosen or the self as the problem, rather than seeing the other as the problem, is a step in the direction of a theology that can welcome all, for all are equally in need of God’s salvation. This step is taken in other “day of the Lord” passages in Isaiah, which look forward to a day of salvation not just for Israel but for all (for example, 2:2-4). Nevertheless, Israel’s positive “day” can still remain terribly negative for the nations (25:9-12).
Although First Isaiah uses the Day of the Lord theme more often than any of the other eighth-century prophets, it shows up only once or twice in Isaiah 40-66 (positively in 52:6; see a related use in 63:4, negatively). Perhaps because of the ambiguity of the Day of the Lord theme, it was not one of the traditions of God’s future that lent itself well to the fuller universalistic perspective of God’s saving work in the second half of the book.