The Greek text says literally “And thus I saw the horses in the vision and the riders on them having fiery breastplates.” The Greek manuscripts have no punctuation marks; all such marks are inserted by editors of the printed Greek text. It is possible therefore that the Greek text means what Revised Standard Version has, that is, only the riders wore the breastplates (also New Revised Standard Version, Biblia Dios Habla Hoy, Barclay, New Jerusalem Bible, Bible en français courant); but it is also possible that the text means what Good News Translation says, that is, that both riders and horses had breastplates (so Revised English Bible, Nova Tradução na Linguagem de Hoje, Translator’s New Testament, New International Version); see Rev. 9.9. On the whole it appears that the form of the Greek text favors Good News Bible, but a translator should feel free to follow the Revised Standard Version rendering. Breastplates in this context may also be expressed as “armor protecting their chests” or “metal plates protecting their chests.”

In my vision: this is the only place in the book where the noun vision is used; the meaning is elsewhere always expressed by the verb “I saw.” Vision in many languages will be translated as “dream.”

The riders: as in the case of the riders of the four horses in 6.2, 4, 5, 8, the text does not say whether they are human or angelic (or demonic) beings; if in translation a specific term must be used, it seems better not to identify them as human beings. If possible the translation should say “those who were riding them.”

The color of fire and of sapphire and of sulphur: that is, red, blue, and yellow (see Good News Translation). The sapphire is a precious stone, usually dark blue. Sulfur is a yellow substance that burns with great heat and produces an unpleasant smell. If specific terms for sapphire and sulfur are not readily available, the translation can say simply “blue and yellow.” But sulfur appears later in this verse and also in the next verse. It will be helpful in the case of sulphur to include an explanatory note in the glossary. See also A Handbook on the Book of Psalms, page 114.

Alternative translation models for this clause are:

• They had armor protecting their chests, which was red like fire, blue like sapphires, and yellow like sulphur.

Or:

• The metal plates protecting their chests were red like the color of fire, blue like a sky-colored precious stone, and yellow like sulphur.

Like lions’ heads: as in 4.7, these horses had heads like those of lions.

Fire and smoke and sulphur issued from their mouths: the picture is something like that of a dragon belching flames.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .