This is the actual content of Yahweh’s oath. A connector such as “namely” helps to introduce the oath. However, many modern versions render this verse without an introductory particle (so Good News Translation).
In Hebrew the first two lines of this verse form the following chiasmus: I will break the Assyrian > in my land > < upon my mountains < [I will] trample him under foot.
That I will break the Assyrian in my land: Yahweh will smash Assyrian power. Instead of break, Good News Translation uses “destroy” and Contemporary English Version “wipe out.” The Assyrian is literally “Assyria” (New Jewish Publication Society’s Tanakh, New Jerusalem Bible). It refers to the Assyrian army occupying the LORD’s land. My land refers to Judah. The Assyrian occupation in view here is probably the one during the time of King Hezekiah in 701 B.C. (see the introductory comments on this section [14.24-27]).
And upon my mountains trample him under foot is parallel to the previous line. Both lines use metaphors. My mountains is parallel to my land and refers also to the land of Judah. Trample him under foot is a typical way of speaking about victory over an enemy in the Old Testament (see Psa 68.30; 91.13). Contemporary English Version uses “crush.” The pronoun him refers back to Assyria. Translators should use an appropriate pronoun (also for his in the next two lines). If the Assyrian is rendered “the Assyrians” in the previous line, then the pronoun should be “them” (Good News Translation). If it is “the Assyrian army,” a good pronoun is “it.”
After the first two lines of this verse New American Bible inserts 8.21-22. However, translators should not do this since there is no textual support for it.
And his yoke shall depart from them: The connector and introduces the result of Yahweh’s actions, so New Jerusalem Bible begins this line with “Then.” Another possible connector is “As a result.” The yoke is a metaphor for oppression (see 9.4; 10.27). His yoke refers to the Assyrian oppression of Judah. The pronoun them points to the people of Judah. This pronoun may be rendered “my people.” His yoke shall depart from them means that Yahweh will actually remove it, not that it will somehow remove itself. Good News Translation makes this clear, as does Bible en français courant with “They [the Assyrians] imposed on my people the yoke of their domination, I will make it disappear.”
And his burden from their shoulder: This line is parallel to the previous one. It also uses metaphorical language to describe the removal of oppression. The Assyrian occupation of Judah is likened to a burden or load that the people of Judah had to carry. Yahweh promises that he will free them from it. In languages where yoke or burden cannot be used as images of oppression, translators will need to find different idioms, or render it in nonfigurative language; for example, “I will stop the oppression imposed by the Assyrians on my people.”
Translation examples for this verse are:
• … [namely] that I will smash the Assyrian army in my land, and on my mountains trample it under foot; then its oppressive yoke will no longer be upon the people of Judah nor its burden on their shoulder.”
• I will smash Assyrian power in my country and on my mountains tread it down; then the yoke of oppression will be lifted from my people and its burden removed.”
• I will smash the power of Assyria in my land
and on my mountains trample it under my feet;
that is how I will remove Assyria’s oppressive yoke from Judah,
the burden it has placed on her shoulders.”
• He will smash Assyrian power in my country and on my mountains he will trample it down. Then the yoke of oppression will be lifted from my people and its burden removed.
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 .