Another angel: this angel is not identified by name or function.

Ascend from the rising of the sun: this angel appears on the horizon, coming from the east. In some languages it will be necessary to state where the angel is ascending to. The following verses indicate that it is heaven. So one may say “coming up to heaven from the east.”

With the seal of the living God: this is not the same as the seals used to close up the scroll in chapters 5 and 6. The seal referred to here is an instrument that marks or stamps a figure, symbol, number, or name upon an object or person. Kings and other important people had such seals, sometimes attached to a ring, called “a signet ring” (see Gen 41.42; Est 3.10; Dan 6.17). The normal purpose of the seal was to identify a document as authentic; the kind of seal spoken of in 5.1 and 20.3 was used to prevent the thing sealed from being opened (see Matt 27.66, the sealing of Jesus’ tomb). In this case the seal is a mark that shows that those who have it on their foreheads are God’s people (see the use of the verb “to seal” in 2 Cor 1.22; Eph 1.13; 4.30). Where an instrument like a stamp or a brand is not known, a descriptive phrase may be used, “an instrument to mark people,” “an instrument to write a sign on people.”

The phrase the seal of … God means the seal that God uses, or the seal that puts God’s mark on people. It is not said whether the identifying mark is a number, a symbol, or a name; 14.1 speaks of 144,000 who have the names of God and of the Lamb on their foreheads (see also 22.4), and it may be assumed that this is true here (see verse 3).

For the living God see the similar divine name “the living one” in 1.18.

Power to harm earth and sea: the passive who had been given means that God had given them this power. The four angels who restrain the winds have the power to turn them loose and cause damage to the earth and the sea. For harm see also 6.6. By “harming the sea” the writer may have had in mind the damage done to islands in the sea; a translation, however, must say simply “the sea” here and in the next verse. The Hebrews thought of seas as having either fresh or salt water, and for the most part were only acquainted with the Mediterranean Sea, the Sea of Galilee, and the Dead Sea. However, sea here in Revelation is referring to all large bodies of water, whether oceans (seas) and lakes, but not rivers. In cultures where such masses of water, whether salty or fresh, are unknown, perhaps one must translate sea here and elsewhere as “large expanses of water.” Earth here refers to “dry land” in contrast with the waters.

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 .