18:1 The land of buzzing wings is as good as dead, the one beyond the rivers of Cush,
“The land of buzzing wings” is Cush, which included modern-day southern Egypt, Sudan, and northern Ethiopia. This nation was named after Cush, the son of Ham, and the father of Nimrod. Father Cush must have possessed a rebellious spirit against Jehovah, because he named his son “Nimrod,” meaning “let us rebel.”
The buzzing wings may refer to the locusts which were prevalent in that area. There were two main rivers of Ethiopia (Atbara and Blue Nile). Both of these rivers were the source of Egypt's Nile River. Isaiah predicted that the Cushites would die. All of these prophecies of invasion and destruction were fulfilled from about 730 B.C. to about 670 B.C.
18:2 that sends messengers by sea, who glide over the water’s surface in boats made of papyrus. Go, you swift messengers, to a nation of tall, smooth-skinned people, to a people that are feared far and wide, to a nation strong and victorious, whose land rivers divide.
The Cushites sent envoys and ambassadors to other nations in swift-moving papyrus boats. Moses was placed in a miniature boat of this kind. The Cushites were tall, fearsome, and aggressive. Their people were called Nubians. Cush was divided by the branches of the Nile River. There was an Ethiopian dynasty established in Egypt about 714 B.C. They pursued an anti-Assyrian policy similar to that of King Hezekiah. Isaiah warned Israel against being involved in any Ethiopian alliance.
18:3 All you who live in the world, who reside on the earth, you will see a signal flag raised on the mountains; you will hear a trumpet being blown.
Isaiah gave a prophetic message to all of the nations of the world who desired to see Assyria fall. They were told to watch and listen. There was no reason for the Cushites to make an alliance with Israel. They would know when the time came to fight. They would see the Assyrians fall.
18:4 For this is what the Lord has told me: “I will wait and watch from my place, like scorching heat produced by the sunlight, like a cloud of mist in the heat of harvest.”
Jehovah told Isaiah that He was being patient with Assyria. His sovereign plan against Assyria would be longer than the summer heat and the harvest dew.
18:5 For before the harvest, when the bud has sprouted, and the ripening fruit appears, he will cut off the unproductive shoots with pruning knives; he will prune the tendrils.
After Assyria performs her task of punishing the people of Israel by taking them captive, then God will judge Assyria. The ripening of the fruit demonstrates that Assyria was ready to perform this service for God. Since God is an all-wise farmer, His pruning activity will never be too early or too late.
18:6 They will all be left for the birds of the hills and the wild animals; the birds will eat them during the summer, and all the wild animals will eat them during the winter.
After Assyria performs God’s service of punishing Israel, then God will cut her off of the tree like fruit. All of the wild animals and birds will come eat her dead bodies.
18:7 At that time tribute will be brought to the Lord who commands armies, by a people that are tall and smooth-skinned, a people that are feared far and wide, a nation strong and victorious, whose land rivers divide. The tribute will be brought to the place where the Lord who commands armies has chosen to reside, on Mount Zion.
During the Millennial Kingdom, the Ethiopian eunuch who accepted Christ is perhaps a type of Ethiopia's future conversion. There has been an Ethiopian church for decades. They also claim to possess the Ark of the Covenant.