This verse identifies Assyria as Yahweh’s enemy. In 10.5 Yahweh speaks of Assyria as his “rod,” which he will use as a weapon against his people. Here it says Yahweh will strike Assyria itself with his rod. This is an interesting reversal.

In Hebrew this verse begins with the particle ki. It is most likely an emphatic marker here, so New Jerusalem Bible renders it “Yes,” and New Jewish Publication Society’s Tanakh has “Truly.” However, like Revised Standard Version and Good News Translation, most versions leave it implied, which is acceptable.

The Assyrians will be terror-stricken at the voice of the LORD: For The Assyrians, see the comments on 7.17. The voice of the LORD is the same one that is mentioned in the previous verse. Once the Assyrians hear Yahweh’s powerful voice they will be terror-stricken, which means they will be terrified. For the Hebrew verb here see the comments on 8.9, where the same verb is rendered “be dismayed.”

When he smites with his rod: His rod refers to the agent Yahweh will use to punish the Assyrians. It is not clear who or what that agent is. For this figurative use of rod, see the comments on 10.5. Compare also “the descending blow of his arm” in the previous verse.

For the translation of this verse we suggest the following examples:

• The Assyrians will be terrified when they hear Yahweh’s voice,
when he attacks them with his stick.

• The Assyrian army will be thoroughly scared when Yahweh speaks,
when he strikes them with his rod.

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 .