Revised Standard Version starts a new paragraph here since Holofernes now says what he will do with Achior. Translators may do what they feel is natural in their language.

You, Achior, you Ammonite hireling: Good News Translation translates “Achior, you are nothing but an Ammonite mercenary.” This conveys the insult implicit in you Ammonite hireling that he has been hired by the Israelites. So one may translate “You are being paid by the Israelites” (compare verses 1-2).

Who have said these words on the day of your iniquity: This is an awkward clause, which means “Your words today have made this day the day of your iniquity.” The real translation problem is finding the appropriate shade of meaning for iniquity. This is a word generally used with reference to offenses against God. New English Bible takes the meaning as “treason,” an offense against his Assyrian overlords (similarly Good News Translation). New English Bible also has a literal understanding of on the day, so it translates “the words you have spoken today are treason.” Other versions interpret on the day figuratively in relationship to iniquity; for example, “a moment of perversity” (New American Bible) and “in a rash moment” (New Jerusalem Bible, also Gonzáles and Alonso-Schöckel). Translators are urged to follow the interpretation taken by Good News Translation and New English Bible. An alternative model is “As you spoke those words today, you were being disloyal to [or, betraying] us.”

You shall not see my face again: This is a conscious note of irony. The next time Achior sees Holofernes, it will be his head only, at 14.6.

Until I take revenge on this race that came out of Egypt: For revenge see 1.12. Holofernes refers literally to the Israelites as “the race/people out of Egypt.” New American Bible translates literally with “this race of people from Egypt,” but this is completely misleading. The Israelites are not from Egypt in any way other than what Achior explained in 5.10-12—they were temporary residents who were enslaved while there. That is where the focus should surely be; Good News Translation feels certain enough of this to omit any reference to Egypt as a geographical entity in “this race of runaway slaves.” Contemporary English Version keeps the reference to Egypt, but shows the temporary residence of the Israelites with “those people who escaped from Egypt.” The word race can be misleading and raise unnecessary questions. Moore’s “nation” or even “people” is more neutral and still literal. But New English Bible‘s “brood of runaways” or Revised English Bible‘s “brood of fugitives” conveys the implicit insult. Translators should try to find a similar expression that conveys the idea of an insult.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Judith. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here.