On that day: See the comments on 2.11. Good News Translation gives the phrase a general meaning here, not related specifically to the events described in the previous verses: “A time is coming.” However, most translations render it as reference to the time of the previous events; for example, New Jerusalem Bible says “When that day comes.”

The LORD will punish the host of heaven, in heaven is literally “Yahweh will visit upon the army of the high place in the high place.” The context indicates that the verb “visit” has the sense of punishment here (so Revised Standard Version, Good News Translation). The verb “visit” is one of the key verbs in chapters 24–27 (24.21-22; 26.14, 16, 21; 27.1, 3). It can have a positive or negative sense, depending on the context (see the comments on this verb at 23.17, where it is used positively). The host of heaven could refer to the angelic beings, but the sun, the moon, and the stars in the sky are likely in view here (see the comments on “the LORD of hosts” at 1.9). Some Israelites believed these heavenly bodies regulated human life, so they worshiped them (Deut 4.19; 2 Kgs 17.16). For this phrase New Jerusalem Bible has “the armies of the sky,” and Bible en français courant says “the army of the stars.” The LORD will punish this “army” in heaven, that is, in the sky.

And the kings of the earth, on the earth: The LORD will also punish the rulers on earth. The verb punish is implied from the previous line, so some translators may want to repeat it here.

The two parallel phrases, the host of heaven and the kings of the earth, are used together to refer to the whole cosmos. The LORD will punish all of creation.

For the translation of this verse consider the following examples:

• At that time Yahweh will punish the heavenly forces in the sky,
he will also punish the kings of the earth on earth.

• When that time comes, Yahweh will judge the celestial powers in the heavens,
and earthly rulers on earth.

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 .