And when the men of Israel retired. — This merely repeats with more graphic details the fact already mentioned in Judges 20:31. The “when” should be omitted, and from “Benjamin began” to the end of the next verse is parenthetic.
Related Commentaries of Judges 20:39
Judges 20:39
39 And when the men of Israel retired in the battle, Benjamin began to smitef and kill of the men of Israel about thirty persons: for they said, Surely they are smitten down before us, as in the first battle.