This verse mentions five times the word “flesh.” That word refers to the body in its (sin-induced) finiteness (Isaiah 40:6). In the present passage we are to understand that this flesh is deceased; the corpses, that is, the kings and captains and mighty men and their horses and their riders, indeed all men whether free or slave, small or great, are dead. The sword from the Rider’s mouth has killed them. The dead should be buried, but when the dead consist of entire armies, their sheer number makes burial (or even cremation) impossible. In his creation God has appointed certain species of birds to clean up decaying flesh (Genesis 40:19; Deuteronomy 28:26; 1 Samuel 17:44, 1 Samuel 17:46; Jeremiah 7:33). That these birds are now summoned speaks to the fact that the dead are too numerous to be given fitting final respect. It should further be noted how this verse underscores that death is the great leveller. Whether king or captain, horse, or rider, free or slave, makes no difference to vultures.
18 to eat the flesh of kings, the flesh of captains, the flesh of mighty men, the flesh of horses and their riders, and the flesh of all men, both free and slave, both small and great.”