This verse ends Yahweh’s short speech. Here he comforts his people in exile by telling them he has forgiven them completely and will rescue them. He uses highly poetic language to express this.
I have swept away your transgressions like a cloud means Yahweh has forgiven the Israelites completely, so he will remove the punishment of their sins, which is their exile in Babylonia. For the Hebrew verb translated have swept away, see the comments on 43.25, where it is rendered “blots out.” This verb is in the perfect form in Hebrew, which usually refers to a completed action. In prophecy the perfect verb form can be used for a future event that will definitely happen. It may have that sense here. However, all the versions consulted use the perfect tense, indicating a completed action. For transgressions see 43.25. Like a cloud is a simile that means like a dark cloud that is blown away by the wind. Translators can make the simile more explicit by rendering this line as “I have taken away [or, removed] your transgressions like the wind blows away a [dark] cloud.”
And your sins like mist is parallel to the previous line. The phrase I have swept away is implied here. This line means God has completely removed the sins of his people like mist, that is, like the sun evaporates mist.
Good News Translation, Bible en français courant, and Die Bibel im heutigen Deutsch use only one simile here. Like Good News Translation, Bible en français courant keeps the first one, saying “like a cloud that passes.” Die Bibel im heutigen Deutsch retains the second one, saying “like mist before the sun.” If possible, translators should keep both similes.
Return to me, for I have redeemed you: Return to me has a double sense here. First, Yahweh is telling his people to worship him truly again. Second, he is calling them to return to Jerusalem, where he dwells, as in 10.21-22 and 35.10. For I have redeemed you is the reason why they should return to him. For this whole clause see the comments on 43.1. Here God assures his people that he will rescue them from exile in Babylonia. The Hebrew verb rendered have redeemed is in the same perfect form as the verb translated have swept away. God speaks of the future return from exile as already accomplished. However, most versions use the perfect tense here, indicating a completed action. There are some exceptions; for example, Good News Translation uses the present tense, which hints at habitual action: “I am the one who saves you.” Die Bibel im heutigen Deutsch has the future tense, saying “because I will set you free.” These are valid options.
Translation examples for this verse are:
• I have blown away your transgressions/offenses as though they were a mere cloud,
and your sins as though they were just mist.
Come back to me, because I have redeemed you.”
• I have swept away like a cloud all your transgressions,
and your sins like mist have disappeared.
Return to me. I have restored 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 .