A.T. Robertson Commentary Revelation 11:7

"And when they shall have finished their testimony, the beast that cometh up out of the abyss shall make war with them, and overcome them, and kill them." — Revelation 11:7 (ASV)

When they shall have finished (οταν τελεσωσιν). Merely the first aorist active subjunctive of τελεω with οταν in an indefinite temporal clause with no futurum exactum (future perfect), "whenever they finish."

The beast (το θηριον). "The wild beast comes out of the abyss" of 9:1f. He reappears in 13:1; 17:8. In Da 7:3 θηρια occurs. Nothing less than antichrist will satisfy the picture here. Some see the abomination of Da 7:7; Matthew 24:15. Some see Nero redivivus.

He shall make war with them (ποιησε μετ' αυτων πολεμον). This same phrase occurs in 12:17 about the dragon's attack on the woman. It is more the picture of single combat (2:16).

He shall overcome them (νικησε αυτους). Future active of νικαω. The victory of the beast over the two witnesses is certain, as in Da 7:21.

And kill them (κα αποκτενε). Future active of αποκτεινω. Without attempting to apply this prophecy to specific individuals or times, one can agree with these words of Swete: "But his words cover in effect all the martyrdoms and massacres of history in which brute force has seemed to triumph over truth and righteousness."