Here Yahweh says he will destroy the city of Babylon.

Thus says the LORD, your Redeemer, the Holy One of Israel: For the fixed formula Thus says the LORD, which is characteristic of prophetic speech, see the comments on 7.7. For the title your Redeemer, see the comments on 41.14. The pronoun your is plural, referring to the Israelites. For the Holy One of Israel, see 1.4.

For your sake I will send to Babylon: The phrase For your sake indicates that when Yahweh destroys Babylon it will be for the benefit of the Israelites. Good News Translation makes this explicit by saying “To save you.” Many languages will require an object for the verb send. Good News Translation, Contemporary English Version, and Revised English Bible add “an army,” while Bible en français courant suggests simply “someone,” which we prefer. The Hebrew verb for send is in the perfect form, so it refers to a completed action. An alternative rendering of the whole line that expresses this is “For your benefit I have sent someone to Babylon.”

And break down all the bars: There is a textual problem here. Instead of all the bars, Masoretic Text has “fugitives all of them.” RSV/NRSV, New Jerusalem Bible, New American Bible, and New Jewish Publication Society’s Tanakh emend the text to refer to “bars,” which are probably prison bars in this context. New Jerusalem Bible makes this explicit by rendering the whole line as “I shall knock down all the prison bars.” If translators follow this reading, they may use a more general term for bars, such as “barriers” or “obstructions.” Good News Translation renders it freely with “city gates,” which we do not recommend. Hebrew Old Testament Text Project supports the Masoretic Text reading of “fugitives.” New International Version follows this reading by rendering the whole line as “and bring down as fugitives all the Babylonians.” Revised English Bible is similar with “and lay the Chaldaeans prostrate as they flee.” Translators have a choice here, but we recommend following Masoretic Text. The first example below keeps the idea of “fugitives,” while the second one has the idea of bars.

And the shouting of the Chaldeans will be turned to lamentations: Chaldeans is another name for Babylonians (see the comments on 13.19). In this context the shouting refers to the joyous or boastful claims of the Babylonians who hold the Israelites captive. Their shouting will turn into lamentations, that is, weeping. However, instead of to lamentations, Masoretic Text has “in ships.” Revised Standard Version has emended the Hebrew text for its reading, which most versions follow; for example, Revised English Bible renders this line as “their cry of triumph will turn to lamentation.” There is no support for this emendation, so Hebrew Old Testament Text Project recommends retaining Masoretic Text. According to the last two lines in Hebrew, when Yahweh destroys the Babylonians, they will try to flee in their ships, in which they had celebrated previously. Traduction œcuménique de la Bible expresses this sense by rendering both lines as “I will bring down the Chaldeans as fugitives in the ships in which resounded their shouts” (similarly New International Version, Die Bibel im heutigen Deutsch). Translators may choose either reading here.

Whichever text translators follow for this verse, they should add a footnote indicating that the Hebrew is unclear. Several possible examples for it are:

• The LORD is your Redeemer, the Holy One of Israel;
this is what he says:
“I have sent someone to Babylon for your sake
to bring down [or, destroy] all the Babylonians,
as they flee on the boats where their joyous shouts have resounded.

• Thus says Yahweh, your Redeemer and Israel’s Holy One:
“I have sent someone to Babylon for your benefit
to break down all its barriers,
and to turn the joyous shouts of the Babylonians to weeping.

Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .