Some modern versions, such as Moffatt, Bible de Jérusalem, and Jerusalem Bible/New Jerusalem Bible, transpose this verse to follow verse 12 because both verses speak of a plague. There is no support for this change in the textual tradition, and discourse analysis does not suggest it. Translators should avoid it.
A plague like this plague: These words refer back to verse 12, and state that the same kind of epidemic that hit the enemy army will also affect their transport animals and other animals. If it is possible to use the same term for a plague affecting animals as that for one affecting people, then translators should do so. However, in some languages a different term may be necessary. Good News Translation uses the general term “A terrible disease,” as in verse 12.
Shall fall on: This metaphor is not in the Hebrew and translators need not try to retain it. Other modern versions use words like “strike” (New International Version, New Jewish Publication Society’s Tanakh, Contemporary English Version, New Living Translation) and “afflict” (New Jerusalem Bible).
The horses, the mules, the camels, the asses, and whatever beasts may be in those camps: The horses were the animals used in battle to pull chariots or to carry cavalry soldiers. Mules are animals of mixed breed, the offspring of a horse of either sex and a donkey of the opposite sex. They are excellent pack animals. Camels are animals that can endure long periods in dry areas. Asses, or in modern language “donkeys,” are the most common beasts of burden (compare 9.9; Ezra 2.66-67; Neh 7.68-69).
Beasts is a term that refers to animals in general, but in a military context like this, it may refer to animals like sheep and goats that could be killed to feed the army. All the animals belonging to the enemy army will suffer the same kind of fate as that described for the human enemy in verse 12. Those camps, though not mentioned before, must refer to the places where the forces that had come to attack Jerusalem had set up their quarters. In those camps may also be expressed as “in the places where the enemy soldiers had set up their tents.”
Quoted with permission from Clark, David J. & Hatton, Howard A. A Handbook on Zechariah. (UBS Helps for Translators). New York: UBS, 2002. For this and other handbooks for translators see here .
