Isaiah was sent to a nation in decline. Judah had repeatedly turned away from God, ignoring the warnings of the prophets, and now faced a time of uncertainty and real danger. Around them, world powers were rising, pressing in on God’s people as a consequence of their sins. God warned that He would remove the hedge of protection surrounding Judah (Isaiah 5:5) and allow the nations to execute judgment for their transgressions.
As these powers advanced, Judah began to put their trust in them rather than in God. Yet the prophets called the people back to faith, insisting that security came only from Yahweh. From chapter 13 through 23, Isaiah speaks to a host of nations—Babylon, Assyria, Philistia, Moab, Damascus, Ethiopia, Egypt, Elam, Media, Arabia, and Tyre—reminding Israel that God’s judgment and sovereignty extend beyond Judah, encompassing all nations. Indeed, chapters 24 to 27 make it clear: the whole world is under God’s control.
Among these nations, Assyria was the mightiest, advancing like a relentless flood against God’s people (17:12–14; 59:19). To the south, Cush—known today as Ethiopia—was the second-strongest power (18:1–7). Isaiah describes Cush as swarming like hordes of flies, emphasising their swift, unstoppable movement into the remotest regions. The prophet’s imagery of wings captures both the buzzing of insects across the land – like mosquitoes in the rainy season – and the speed of envoys travelling on papyrus boats along the Nile.
The region of Cush was much larger than modern Ethiopia; some believe it extended from the Congo Basin to Egypt. By the 8th century BC, when Isaiah was writing, this area was under the 25th Dynasty, incorporated into Egypt and ruled by Cushite rulers. Isaiah’s audience would have understood him to be speaking of sub-Saharan, or “black Africa,” which was at that time a powerful presence on the world stage.
Scholars debate many details of this passage. Is Ethiopia receiving God’s message, or acting as His messenger? Is the judgment directed at Ethiopia, at Assyria, or at the nations in general? These uncertainties, however, only underscore the central truth: no nation will ultimately triumph. God alone is sovereign. He holds the nations in his hands and will judge them for their pride and arrogance.
Even in the midst of judgment, God’s grace would triumph and extend even to the Gentiles. The book of Isaiah repeatedly points to this hope (14:1–4, 32; 16:1–6), and Israel was reminded to proclaim God’s glory to all the earth: “Sing praises to the LORD, for he has done gloriously; let this be made known in all the earth” (12:5). God’s power will be witnessed worldwide, and the Gentiles will come to worship him; “At that time tribute will be brought to the LORD of hosts from a people tall and smooth, from a people feared near and far, a nation mighty and conquering, whose land the rivers divide, to Mount Zion, the place of the name of the LORD of hosts.”
In the Old Testament, the worship of Yahweh was centered in Jerusalem (1 Kings 8:29; 2 Kings 23:27), but in the New Testament, God’s dwelling is fulfilled in the body of Christ, the Church. The Psalmist also points to this fulfilment: “Nobles shall come from Egypt; Cush shall hasten to stretch out her hands to God” (Psalm 68:31).
These prophecies concerning Cush were fulfilled in the conversion of the Ethiopian eunuch (Acts 8:26-38). But they stretch even beyond Cush, for God’s purpose and his glory will be known across the world; to “all the earth” (12:5).