Our reading today continues the oracles against the nations, and it begins with an oracle against Egypt. The imagery of God riding on a cloud refers to judgment (19:1 – see Dan 7:13-14, Matt 24:30, Rev 1:7). Here, Egypt will be judged internally through civil war (v. 2) and attack from without (v. 4). Like at the Passover, God will judge not just Egypt, but her gods (v. 1, 3 – see Ex 12:12). The land will be left desolate (vv. 5-10). Zoan was Egypt’s capitol at this time (v. 11). In verses 11-13 we see that the wisdom of the world is foolishness (see 1 Cor 3:19). Memphis was the center of religious worship in Egypt, including Pharaoh worship. In verses 14-15 we see the sovereignty of God over judgment and therefore the completeness of this judgment against Egypt.
In verses 16, 18, 19, 21, 23, and 24 we have our “in that day” again. In verses 16-25, we see a description of the ultimate inclusion of foreign nations (here, Egypt and Assyria) in the people of God. In verses 16-17, we see that Egypt will fear the Lord. In verse 18, we have “five cities” that will speak the language of Canaan (referring to Hebrew), meaning they will be assimilated into the Jewish culture. In verse 9, we see that an altar to YHWH will be built in Egypt. During the Babylonian captivity, there will be Jews that will escape to Egypt (see Jer 44:1) and literally build places of worship to YHWH and integrate the Egyptian culture with their own.
However, this has a dual fulfillment. It is picturing YHWH worship spreading throughout Egypt (vv. 18-22) and then beyond all the way to Assyria (v. 23) and then both will be included with Israel in receiving God’s blessing (vv. 24-25). Both the judgment and the salvation of the day of YHWH will include Egyptians (v. 22). Then the nations will worship YHWH (v. 23). Egypt and Assyria will become part of God’s people along with Israel (v. 25). This is picturing the inclusion of the nations in the covenant and final salvation.
Chapter 20 records a sign-prophecy of Isaiah (prophesying by act rather than words). That this account is in the third person may indicate that one of Isaiah’s disciples wrote this portion of the book. God commands Isaiah to live his life naked and barefoot for three years (20:2-3). His nakedness symbolizes prisoners of war who would be stripped naked to be shamed by their captors. Isaiah is giving a sign that Egypt and Cush would be overtaken by Assyria and sent into captivity (vv. 3-4). Nakedness also symbolizes shame over sin (see Gen 3:7). God then indicts the nations that foolishly looked to Egypt and Cush for protection against Assyria (v. 6).
Chapter 21 finishes the oracles against the nations with an oracle against Babylon. An attacker is likened to the desert winds from the south of Judah (21:1). This is Persia. Elam and Media are lands of Persia, who would overthrow Babylon as the dominate world power (v. 2). This would be God’s judgment against Babylon. Isaiah is very dismayed by the vision he sees (vv. 3-4). Babylon will be eating and drinking as usual when Persia strikes (v. 5 – see Daniel 5). God calls for a watchman to be set to keep guard (vv. 6-7). This points to the surety of the coming judgment, as the watchman sees exactly what God said he would (vv. 8-9a). Babylon will fall (vv. 9b-10 – see Jer 51:8). This idea of Babylon falling is used as a metaphor for all worldly powers in Revelation 14:8 and 18:2
In verse 11, we have an oracle concerning “Dumah,” which literally means “silence” in Hebrew. This parabolic passage speaks to the fact that even though the judgment has not yet come, Babylon should not think it won’t. The image is of someone asking the watchman (from vv. 6-10) when the judgment is coming, and the watchman saying days keep passing with nothing in sight. In verses 13-15 we see that Babylonians will flee into the Arabian desert when Persia overthrows them like Judahites will flee to Egypt when Babylon overthrows them. Verses 16-17 again speak to the certainty of the coming judgment.