Here Yahweh says he himself will besiege Jerusalem, which means he is behind the enemy nation (probably Assyria) doing it. The three parallel lines of this verse are nearly synonymous, so they emphasize Yahweh’s action against the city.

And I will encamp against you round about describes Yahweh using enemies to surround Jerusalem. The Hebrew verb for encamp means “besiege” here (see the comments on Isa 29.1). Instead of round about, the Septuagint says “like David.” It emends the Hebrew text since it is obscure. New Revised Standard Version and New American Bible follow the Septuagint, and New Jewish Publication Society’s Tanakh puts its reading in a footnote. Hebrew Old Testament Text Project, however, does not mention this textual problem. We recommend the traditional reading in Revised Standard Version. This line may be rendered “And I will besiege you on all sides.”

And will besiege you with towers is literally “and I will besiege against you a palisade/fence.” The phrase “against you” is used three times in this verse for emphasis. The Hebrew noun rendered towers comes from a root meaning “to stand upright,” so New Jewish Publication Society’s Tanakh suggests “a mound.” This word can refer to an army or garrison, so Revised English Bible says “a ring of outposts.” However, it seems better to render it “siege towers” here since it is parallel with siegeworks. For “siege towers,” see 23.13. New International Version translates this line as “I will encircle you with towers.” Good News Translation simply says “surround it,” which is fine.

And I will raise siegeworks against you: Siegeworks refers to all the offensive instruments used to besiege a city, such as siege walls, siege mounds, and siege towers. A general term should be used to include all these instruments.

The following translation examples express the three parallel lines of this verse as closely synonymous:

• And I will set up a siege around you,
and erect siege towers against you,
and build ramparts against you.

• And I will set up camp around you,
and besiege you with an army,
erecting offensive works against you.

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 .