Revelation 18:6

Render to her just as she rendered to you
Render is ἀπόδοτε [apodote] , plural imperative, you all give back to her! Who is this command given to?

According to Rev. Rev. 17:16-17+, it is the false Christ and his allies who will destroy Babylon in compliance with the overarching purpose of God. Further confirmation of this conclusion surfaces in noting that the result of the judgment is the same in both chapters: the burning of the city (Rev. Rev. 17:16+; Rev. 18:8+, Rev. 18:9+, Rev. 18:18+). . . . God puts into the hearts of these enemies to do what they do, so it appears wisest to connect the city’s burning in chapter Rev. 18:1+ with that in chapter Rev. 17:1+.1

The NU text and several MT manuscripts omit to you. The unnamed recipients of what she rendered is probably the whole earth. This is supported by the realization that she has rendered to her enemies throughout history (Rev. Rev. 18:24+). See commentary on Revelation 17:16. She rendered, is αὐτὴ ἀπέδωκεν [autē apedōken] , she, she gave out. The addition of the pronoun in addition to the implicit pronoun found in the verb form emphasizes her bad behavior. Her judgment is based on the law of retribution, not undertaken by the saints, but by God. “O daughter of Babylon, who are to be destroyed, happy the one who repays you as you have served us!” (Ps. Ps. 137:8). “Take vengeance on her. As she has done, so do to her” (Jer. Jer. 50:15b). “Repay her according to her work; according to all she has done, do to her” (Jer. Jer. 50:29b). “As Babylon has caused the slain of Israel to fall, so at Babylon the slain of all the earth shall fall” (Jer. Jer. 51:49).

repay her double according to her works
Under the Law of Moses, restitution of thievery involved interest of 100%—the thief was required to pay double what was stolen (Ex. Ex. 22:4). Even Jerusalem received double for all her sins from the LORD’s hand in judgment (Isa. Isa. 61:7; Jer. Jer. 16:18). When Jeremiah prayed for judgment of his enemies, he asked God to “bring on them the day of doom, and destroy them with double destruction!” (Jer. Jer. 17:18). Jeremiah calls Babylon, מְרָתַיִם [merāṯayim] , meaning double rebellion (Jer. Jer. 50:21):

This word, which is formed by the prophet in a manner analogous to Mizraim, and perhaps also Aram Naharaim, means “double rebellion,” or “double obstinacy.” It comes from the root מָרָה [mārâ] , “to be rebellious” against Jahveh and His commandments.2

in the cup which she has mixed, mix double for her
Having served her cup to the nations, she will now drink from her own cup and suffer derangement at her own hand. Your wisdom and your knowledge have warped you . . . You are wearied in the multitude of your counsels; let now the astrologers, the stargazers, and the monthly prognosticators stand up and save you from what shall come upon you” [emphasis added] (Isa. Isa. 47:10-12). See commentary on Revelation 14:10. See commentary on Revelation 17:4.

Notes

1 Robert L. Thomas, Revelation 8-22 (Chicago, IL: Moody Press, 1995), Rev. 18:6.

2 Carl Friedrich Keil and Franz Delitzsch, Commentary on the Old Testament (Peabody, MA: Hendrickson, 2002), Jer. 50:21.