Revised Standard Version apparently takes this verse to be a continuation of the direct quotation in verse 17, and it is also taken as such, for instance, by New International Version. If a translator regards verse 18 as a continuation of the quotation, he will probably need to retain first-person references to the LORD throughout the verse. In view of the parallel theme between verses 2-3 and verses 17-18, this seems the most probable interpretation. However, Good News Translation takes the verse to be a comment by the prophet, as does Bible en français courant.
Neither their silver nor their gold shall be able to deliver them: this may be another reference to the Scythian invasion. According to Herodotus, when the Scythians reached the borders of Egypt, they were bribed by the Pharaoh to turn back and not to attack his land. Zephaniah here makes the point that no amount of money can buy escape from the punishment of the LORD. Their and them refer to mankind in the previous verse. In some languages it will therefore be helpful to say “not even all the silver and gold of mankind will save them.” In cultures where silver and gold are not used or even known, one may say “How ever rich they are, their money will not help them to escape.”
On the day of the wrath of the LORD: Good News Translation changes the order of the Hebrew phrases so as to put this time phrase first, which it translates as “On the day when the LORD shows his fury.” This follows a more natural order in English and also matches verses 8, 10, 12, and 14, all of which begin with a time phrase.
In the fire of his jealous wrath, all the earth shall be consumed: this whole clause is repeated in 3.8. It is common in the Old Testament to speak of the LORD’s wrath as being like fire (for example, Psa 79.5; 89.46; Isa 30.30; 66.15; Jer 15.14; 17.4; Nahum 1.6), and if possible this figure of speech should be kept in translation. It may be expressed more easily in some languages as a simile or comparison than as a metaphor. The word translated jealous wrath refers to the LORD’s concern for the honor which is rightly his. It does not have the sense common in ordinary English conversation, of envious desire for that which rightly belongs to someone else. See also comments on Nahum 1.2.
As mentioned in the discussion of verse 17, Revised Standard Version understands this verse to refer to a universal judgment by God, and therefore uses the term earth rather than “land,” as in New English Bible. “Land” would refer only to Judah.
The verb translated consumed is literally “eaten.” Good News Translation drops this metaphor and renders as “destroyed,” but some translators may be able to keep it, if it is natural in their language to speak of fire eating things. In languages which do not use the passive, alternative translation models are “The LORD will destroy the whole world (or, earth) with the fire of his anger,” or “The LORD is so angry that he will destroy the whole world as if by fire,” or even “The LORD’s heart is hot just like a fierce fire and will burn up the whole world.”
For a full, yea, sudden end he will make of all the inhabitants of the earth: there is probably another play on the sounds of the Hebrew words here translated as full (end) and sudden end. In many languages it will be impossible to reproduce this play on sounds in Hebrew. In such cases one may say, for example, “he will suddenly kill every person who lives on earth.” This clause is the climax to the lengthy description of the LORD’s judgment, which has taken up most of chapter 1.
Quoted with permission from Clark, David J. & Hatton, Howard A. A Handbook on the Book of Zephaniah. (UBS Helps for Translators). New York: UBS, 1989. For this and other handbooks for translators see here .