Following are a number of back-translations as well as a sample translation for translators of Ezekiel 21:28:

• Kupsabiny: “Ezekiel, prophesy. Call to these Ammonites who insult Israel the words that I the God of power am saying. Tell (them),
  A sword, oh a sword,
  has been drawn to destroy.
  It is washed for killing
  and it flashes/shines like lightning.” (Source: Kupsabiny Back Translation)
• Hiligaynon: “‘And you man, tell the Ammonhon who insult Israel that I, the Lord GOD, (am) the-(one) saying this: The sword is now ready to kill. It is polished very-well so-that [it] will-flash like lightning.” (Source: Hiligaynon Back Translation)
• English: “‘And, you human, prophesy and say this: ‘This is what Yahweh the Lord says about the Ammon people-group, and about what they have said to insult Israel:
  ‘The King of Babylon says,
  ‘My soldiers have swords’ ;
  they have pulled out those swords to slaughter many people.
  They have polished them in order to kill people,
  and to make those swords flash like lightning.” (Source: Translation for Translators)