But with an overflowing flood represents the first two words of the Hebrew of verse 8. Some modern versions take these words with verse 7 and translate “he calls to mind those who trust in him when the flood overtakes them” (Jerusalem Bible) or “he takes care of those who have recourse to him, when the flood rages” (New American Bible; compare Moffatt, Bible de Jérusalem, Traduction œcuménique de la Bible, Bible en français courant, Die Bibel im heutigen Deutsch). This makes good sense, but so does the text as punctuated in the Hebrew manuscripts, and there is no strong reason to depart from it. Indeed if the first two words are taken with the rest of verse 8, as in Revised Standard Version, they can be seen more clearly as applying the LORD’s power over nature (verses 3b-6) to his dealings with people. Good News Translation also takes them this way and translates “Like a great rushing flood.” The word flood may be a reference to the account of the destruction of the wicked at the time of Noah (Gen 6–9). Another way of rendering this sentence is: “He is like a great rushing flood which will completely destroy (or, will kill) his enemies” or “He is like a huge wave which crashes down on his enemies and kills all of them.”
He will make a full end of his adversaries: Revised Standard Version follows the ancient Greek translation, the Septuagint, in translating adversaries (compare Bible de Jérusalem, Jerusalem Bible, New American Bible, New English Bible, Good News Translation, Bible en français courant). The Hebrew at this point has “her place.” Those modern versions which retain the Hebrew take the “her” to refer to Nineveh (Traduction œcuménique de la Bible footnote, New International Version; compare Hebrew Old Testament Text Project). As Nineveh has not been mentioned since verse 1, this seems rather unlikely, and translators are advised to do as Revised Standard Version and Good News Translation have done and follow the Greek. Good News Translation translates in more natural English as “he completely destroys his enemies.”
The second half of the verse repeats the thought of the first part in different words. The Hebrew uses a figure of speech which most English versions translate literally. Revised Standard Version says that the LORD will pursue his enemies into darkness. The sentence can also mean “darkness will pursue his enemies,” but this is less likely, since it involves a change of subject. Darkness stands for the darkness of the underworld, that is, death (compare Job 18.18), and some languages may be able to retain the figure. Good News Translation expresses this in nonfigurative language as “he sends to their death those who oppose him.” One may also say “He sends to their death all those who hate him.” In some languages “he sends to their death” may be a difficult expression. In such a case one can say “He causes those who oppose him (or, his enemies) to die.”
Quoted with permission from Clark, David J. & Hatton, Howard A . A Handbook on the Book of Nahum. (UBS Helps for Translators). New York: UBS, 1989. For this and other handbooks for translators see here .