For this is like the days of Noah to me introduces the special thought that dominates verses 9-10. In this context the Hebrew particle ki rendered For could be a logical connector (so Revised Standard Version) or be an emphatic marker (rendered “Indeed/Truly”). As a logical connector, it introduces why God will show mercy to his people in exile. If it is an emphatic marker, it draws special attention to the historical example of Noah, linking it to the present experience of the Israelites. With either understanding of the Hebrew particle ki there is a link between this verse and the previous ones. The demonstrative pronoun this points back to the situation described in verses 7-8. Like the days of Noah compares the time of the exile to the earlier time of the flood when Noah lived (see Gen 6–9). For the days of Noah, Good News Translation has “In the time of Noah” (similarly Bible en français courant).
As I swore that the waters of Noah should no more go over the earth is the first part of a comparison. As introduces the premise, while the last two lines beginning with so give the conclusion. I swore means that God made an oath or a solemn promise (see the comments on 14.24 and 45.23). The waters of Noah should no more go over the earth is the content of that oath. God promised Noah that he would never destroy the world with a flood again (see Gen 9.8-17). The waters of Noah refers to the water that flooded the earth in Noah’s time. Noah did not own the water, which Revised Standard Version‘s rendering might imply. Good News Translation‘s brief rendering of these two lines expresses the meaning clearly: “I promised never again to flood the earth.” Bible en français courant has “I had promised then [at the time of Noah] that the great flood would not submerge the earth anymore.”
So I have sworn that I will not be angry with you compares the promise made to Noah with that given to the exiles now. Just as God promised Noah that he would never destroy the world again with a flood, so he promises to bring his people back from exile and not punish them in this way again. The new divine oath means the time of punishment for the exiles is about to end (see 40.1-2). The Hebrew verb rendered be angry comes from the same root as the noun translated “wrath” in the previous verse. So God will hold back his intense anger. Although Masoretic Text does not repeat the Hebrew adverb rendered more in the previous line, it is implied here and is present in Dead Sea Scrolls. Good News Translation, Revised English Bible, and Bible en français courant follow Dead Sea Scrolls by using the adverb “again.”
And will not rebuke you does not mean that God will never criticize his people again, because it is clear later in their history that he did so. The Hebrew verb for rebuke means “to act in anger” here, since it is parallel with be angry in the previous line (compare 66.15). Instead of rebuke, Die Bibel im heutigen Deutsch and Bible en français courant say “threaten,” and Good News Translation has “reprimand or punish.”
For the translation of this verse consider the following examples:
• “Now indeed this situation is like that in the time of Noah.
Just as I swore an oath then
that a flood should not cover the earth again,
so I have sworn an oath
that I will not be so angry or act in anger against you again.
• “For this situation is like that in Noah’s day.
Just as I promised then
that floodwater should never cover the earth again,
so I promise now
that I will not be angry or act in anger 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 .