Albert Barnes Commentary Revelation 19:17

"And I saw an angel standing in the sun; and he cried with a loud voice, saying to all the birds that fly in mid heaven, Come [and] be gathered together unto the great supper of God;" — Revelation 19:17 (ASV)

And I saw an angel standing in the sun. Evidently, this was a different angel from the one that had previously appeared to him. The number of angels that appeared to John, as referred to in this book, was very great, and each one came on a new errand, or with a new message.

Everyone must be struck with the image here. The description is as simple as it can be, and yet as sublime. The fewest words possible are used, and yet the image is distinct and clear. A heavenly being stands in the blaze of the brightest of the orbs that God permits us here to see—yet not consumed, and so bright himself that he can be distinctly seen amidst the dazzling splendors of that luminary. It is difficult to conceive of an image more sublime than this. Why he has his place in the sun is not stated, for there does not appear to be anything more intended by this than to give grandeur and impressiveness to the scene.

And he cried with a loud voice, so that all the fowls of heaven could hear.

Saying to all the fowls that fly in the midst of heaven. That is, to all the birds of prey—all that feed on flesh—such as those that hover over a battlefield. (Isaiah 56:9).

See also Jeremiah 7:33; 12:9; Ezekiel 39:4–20.

Come and gather yourselves together. All this imagery is taken from the idea that there would be a great slaughter, and that the bodies of the dead would be left unburied for the birds of prey.

Unto the supper of the great God. This is as if the great God were about to give you a feast: namely, the carcasses of those slain. It is called "his supper" because he gives it; and the image is merely that there would be a great slaughter of his foes, as is specified in the following verse.