And that night: These words are not found in the parallel account in Isa 37.36. But this detail should be retained here.
The angel of the LORD: See the comments at 2 Kgs 1.3. The Hebrew word for angel is the same one rendered “messengers” in verses 14 and 23. Some commentators suggest that the introduction of the angel here is a deliberate attempt on the part of the writer to contrast Yahweh’s messenger with the messengers of Sennacherib.
Went forth; that is, went into the place where the Assyrian army had camped for the night.
Slew a hundred and eighty-five thousand in the camp of the Assyrians: Instead of the archaic word slew, Good News Translation says “killed.” The writer does not tell how the angel caused the Assyrian soldiers to die.
When men arose early in the morning: A literal rendering of this expression may be misleading in some languages since the men referred to cannot be the Assyrian soldiers who were all dead. The term refers rather to people in general, but certainly not the dead people in the Assyrian camp. Some have argued that the expression might possibly mean “When the surviving Assyrians woke up the next morning” (New Living Translation). But since the text uses the word all to describe how many Assyrian soldiers died, this seems unlikely. The expression may therefore be taken as an idiomatic way of saying “at sunrise,” “When the people got up early the next morning” (New Century Version), “when morning dawned” (New Revised Standard Version, Revised English Bible), or “Early the next morning” (New American Bible). The context does reveal that King Sennacherib, at least, did survive.
Behold: See the comments on verses 7 and 9.
These were all dead bodies is perhaps better translated “there were dead bodies all about” (American Bible) or “the camp was full of dead bodies” (Contemporary English Version).
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 2. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .