If any one would harm them: the same verb is used in 2.11; 7.2; 9.4, 10 (“hurting”), 19 (“wound”). Other ways of expressing this are “Whoever tries to hurt them” or “If any person attempts to injure them.”

Fire pours from their mouth: this is like the fire that pours out of the horses’ mouths in 9.17-18. Elijah called down fire from heaven to destroy his enemies (2 Kgs 1.10, 12).

And consumes their foes: one should avoid leaving the reader with the impression that the foes and any one in the first part of the verse are two different sets of people. Perhaps one may translate the first part of the verse as “If any person tries to hurt these two men, fire shoots out of their mouths and destroys these enemies.” Their foes: in certain languages this will be expressed as “the people who hate them.”

Consumes: this translates the Greek verb “eats up”; so something like “kills,” or “destroys,” or any other verb that goes with fire, is a satisfactory translation.

If any one would harm them: this clause is repeated from the beginning of the verse, although in Greek the verb form is different. The literal repetition of this clause may not be effective in some languages, and something like Good News Translation may be preferable.

Thus: that is, by means of the fire. Good News Translation “in this way.”

He is doomed: this translates the impersonal verb “it is necessary,” “it must be,” or “it is proper,” which is generally used of the divine judgment and will (see 1.1). So the final clause may be rendered as “and in this way God will kill whoever tries to hurt them.”

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 .