“Go, you swift messengers, to a nation, tall and smooth, to a people feared near and far, a nation mighty and conquering …” (v2). Isaiah prophesied that the strong people of Cush (either Ethiopia or Sudan) would, just like Damascus and Israel, face their reckoning with God. Their trade and diplomacy along the Nile (v2) would come to an end when God brought His justice. One day, instead of being rebellious idolaters, they would bring “tribute” to Mount Zion and join with God’s people (v7).
“All you inhabitants of the world …” (v3). Isaiah’s prophecies extended beyond Israel to other nations, because God’s desire is that those who are “far off” would be brought near by Jesus’ blood (Eph 2:13).