I heard the altar cry: in some languages it may be impossible to speak of an altar crying out or saying something; in these cases it may be necessary to imitate Good News Translation, “I heard a voice from the altar” (see in 6.9 the souls of the martyrs near the altar). In 8.3-5 the prayers of God’s people are offered on the altar of incense, and here it is probably this altar that is meant. In languages that cannot speak of voices crying, one may need to say, for example, “I heard someone crying out from the altar, saying….”

Yea: something like “Indeed” or “Truly” is better in English. New Revised Standard Version has “Yes.”

Lord God the Almighty: see comments on 1.8; 11.17.

True and just: see 15.3. Since judgments here, as in verse 5, refers specifically to the punishments, the translation can say “your punishments (or, the punishments you send) are fair and well deserved.” Or it is possible to translate “You have judged them fairly and justly.”

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 .