John’s eye had been focused on the open heaven and specifically the white horse and its rider. His eye is now diverted away from heaven to the sun—from heaven’s brightness to creation’s brightness. Silhouetted against the sun’s brightness John sees a single angel. Angels are servants of God whom God sends forth to serve his people (Hebrews 1:14). The juxtaposition of the present verse with the conclusion of the previous—the rider is King of kings and Lord of lords—implies that Jesus Christ has commissioned this angel. He takes his stand in the sun—high in the sky, where all creation can hear him—and shouts out a proclamation to all birds.
17 Then I saw an angel standing in the sun, and with a loud voice he called to all the birds that fly directly overhead, “Come, gather for the great supper of God,