A.T. Robertson Commentary Revelation 20:9

"And they went up over the breadth of the earth, and compassed the camp of the saints about, and the beloved city: and fire came down out of heaven, and devoured them." — Revelation 20:9 (ASV)

They went up (ανεβησαν). Second aorist active indicative of αναβαινω, a return to the manner of the seer as in verses 4,5.

Over the breadth of the earth (επ το πλατος της γης). Πλατος is old word, in N.T. only here, 21:16; Ephesians 3:18. The hosts of Satan spread over the earth.

Compassed (εκυκλευσαν). First aorist (prophetic) active indicative of κυκλευω, to encircle, late verb (Strabo) from κυκλος (circle), in N.T. only here and margin in Joh 10:24 (for εκυκλωσαν from κυκλοω).

The camp of the saints (την παρεμβολην των αγιων). Παρεμβολη (παρα, εν, βαλλω) is common late word for military camp, in LXX for the Israelites in the desert (Exodus 29:14, etc.), in N.T. for Roman barracks (Acts 24:34,37) and for an army in line of battle (Hebrews 11:34; Revelation 20:9).

The beloved city (την πολιν την ηγαπημενην). Perfect passive participle of αγαπαω, "the city the beloved." See Ps 78:68; 87:2 for Jerusalem so described. So Charles takes it here, but Swete holds it to be "the Church the New Zion" that is meant.

And fire came down out of heaven (κα κατεβη πυρ εκ του ουρανου). Second aorist (prophetic) active indicative of καταβαινω. Cf. Genesis 19:24; 39:6; Ezekiel 38:22; 2 Kings 1:10,12; Luke 9:54 (about John).

Devoured them (κατεφαγεν αυτους). Second aorist (prophetic) active of κατεσθιω, to eat up (down). Vivid climax to this last great battle with Satan.