Following are a number of back-translations as well as a sample translation for translators of Nahum 1:15:

• Kupsabiny: “Look, a person is coming from/on the mountain who has good news! He is announcing victory! People of Judah, celebrate your festivals, please, and give to God the things you have promised. Never again shall that sinful king attack your country, because he will be destroyed completely.” (Source: Kupsabiny Back Translation)
• Newari: “Look, there on the mountains,
  the feet of one who brings good news,
  who proclaims peace!
  Oh Judah, celebrate your festivals
  and fulfill your vows.
  For the wicked will no more attack you.
  They will be totally wiped out.” (Source: Newari Back Translation)
• Hiligaynon: “You (plur.) look-at those-(who)-come-from-Juda! There is a messenger who is-passing-through-over the mountains to bring you (plur.) the good news that there is now peace in your (plur.) place. Therefore you (plur.) celebrate your (plur.) feasts and you (plur.) fulfill your (plur.) vows to the LORD. For the wicked nation of Asiria will- never -attack you (plur.) anymore, for they will-be- completely -destroyed.” (Source: Hiligaynon Back Translation)
• English: “You people of Judah, look! A messenger will be coming across the mountains,
  and he will be bringing good news to you.
  He will be declaring that you will now have peace because Assyria will have been conquered.
  So, celebrate your festivals,
  and do what you solemnly promised to do when your enemies were threatening to attack you,
  because your wicked enemies will not invade your country again,
  because they will be completely destroyed.” (Source: Translation for Translators)