Charles Ellicott Commentary Revelation 9:17

"And thus I saw the horses in the vision, and them that sat on them, having breastplates [as] of fire and of hyacinth and of brimstone: and the heads of lions; and out of their mouths proceedeth fire and smoke and brimstone." — Revelation 9:17 (ASV)

And thus I saw . . .—Better, And in this way I saw the horses in the vision, and those who sat on them, having breastplates fiery and jacinth-like, and brimstone-like; and the heads of the horses were as heads of lions; and out of their mouths goes forth fire and smoke and brimstone.

The seer proceeds to describe the general appearance of the horses and horsemen. Their appearance was as follows: the horses and horsemen were armed with breastplates of a triple hue (corresponding to the threefold destructive stream that goes forth from their mouth), the hues of flame, dark purple (jacinth), and brimstone.

The jacinth colour seems to be the dark purple or blue so often seen in smoke. The Poet Laureate uses the word “azure” to describe the colour of ascending columns of smoke (“azure pillars of the hearth arise to you”): the colour here would be darker, the smoke not arising from peaceful dwellings, but generated among death-giving elements.

The army consists mainly of horsemen, and they are described as resolute and relentless: we are reminded of somewhat similar features in the Chaldean armies described by Habakkuk, “I raise up the Chaldeans, that bitter and hasty nation: they are terrible and dreadful: their horses also are swifter than leopards,” and so on (Habakkuk 1:6–10).