The connector Therefore does not fit here since this verse does not describe the direct result of the previous verse. Translators would do well to omit it, following Good News Translation.
When you have come to Babylon you will remain there: This is reduced in Good News Translation to “You will remain there in exile.” This can be done because it is obvious where the Jews are going: after verses 1 and 2, Babylon as a destination does not need to be repeated. (Good News Translation will bring “Babylon” back in at the end of the verse where it seems less obtrusive.) And if they are going to remain there, they obviously have to get there. The only thing that may be missing from the abbreviated wording in Good News Translation is the sense of journeying to Babylon. That in itself was to be a difficult ordeal, and a translation such as New Jerusalem Bible conveys this by saying “Once you have reached Babylon you will stay there.” Good News Translation adds “in exile” to help the reader understand the historical situation, although this would hardly be needed by the original audience. So translators may say something like “Once you have reached Babylon you will remain there.”
Seven generations: Although forty years seems to be the length of a generation in Old Testament thinking, it is best not to translate this into exact numbers. On the one hand, we cannot be sure of that forty-year length, and on the other, we can be pretty sure that the author is being deliberately vague. Jeremiah had spoken of an exile of seventy years in Jer 25.12 and 29.10 (a figure of forty years is given in Ezek 4.6). The earliest exiles to return home departed about 60 years after the first group of captives had been taken to Babylonia, and there were other later groups making their way back in the late sixth century B.C. But 280 years (40 times 7) after the exile began, there were Jews not only in their historic homeland and in Babylonia, but all over much of the known world. In much of this area the warnings of this book to avoid the worship of idols would have been relevant. The reference here to seven generations is one reason that the year 317 B.C. (597 minus 280) is sometimes seen as possibly the year that this book was written, or at least as indicative of the general period of writing—the Greek period in Jewish history.
After that I will bring you away from there in peace: Here God speaks directly. Good News Translation and Contemporary English Version shift this to third person to avoid an awkward transition from the prophet’s words to God’s words and then back to the prophet’s. This difficulty occurs in verse 7 also. Bring you … in peace may not be adequately represented by “lead you peacefully home” (Good News Translation). Peace certainly represents the Hebrew word shalom, which means “peace, prosperity, health, well-being, all good things” (see Bar 3.13). However, Good News Translation is only saying that the people will return home without any armed conflict along the way. This is one aspect of the meaning, of course, but New English Bible appropriately adds another aspect, saying “lead you … in peace and prosperity.” The meaning is close to “send you home with renewed hopes, happy and optimistic.” “Lead you safely home” might convey the idea a bit better than “lead you peacefully home.”
Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Shorter Books of the Deuterocanon. (UBS Helps for Translators). New York: UBS, 2006. For this and other handbooks for translators see here.