New Living Translation
I see a terrifying vision: I see the betrayer betraying, the destroyer destroying. Go ahead, you Elamites and Medes, attack and lay siege. I will make an end to all the groaning Babylon caused.

American Standard Version
A grievous vision is declared unto me; the treacherous man dealeth treacherously, and the destroyer destroyeth. Go up, O Elam; besiege, O Media; all the sighing thereof have I made to cease.

Berean Study Bible
A dire vision is declared to me: “The traitor still betrays, and the destroyer still destroys. Go up, O Elam! Lay siege, O Media! I will put an end to all her groaning.”

Douay-Rheims Bible
A grievous vision is told me: he that is unfaithful dealeth unfaithfully : and he that is a spoiler, spoileth. Go up, O Elam, besiege, O Mede: I have made all the mourning thereof to cease.

English Revised Version
A grievous vision is declared unto me; the treacherous dealer dealeth treacherously, and the spoiler spoileth. Go up, O Elam; besiege, O Media; all the sighing thereof have I made to cease.

King James Bible
A grievous vision is declared unto me; the treacherous dealer dealeth treacherously, and the spoiler spoileth. Go up, O Elam: besiege, O Media; all the sighing thereof have I made to cease.

World English Bible
A grievous vision is declared to me. The treacherous man deals treacherously, and the destroyer destroys. Go up, Elam; attack! I have stopped all of Media's sighing.

Young's Literal Translation
A hard vision hath been declared to me, The treacherous dealer is dealing treacherously, And the destroyer is destroying. Go up, O Elam, besiege, O Media, All its sighing I have caused to cease.

Isaiah 21:2 Additional Translations ...