‘ And the men of Israel retired (‘turned') in the battle, and Benjamin began to smite and to kill of the men of Israel about thirty men, for they said, ‘surely they are smitten down before us as in the first battle'.' Compare Judges 20:31. That working out of the strategy is repeated again here together with its consequence. This time the children of Israel only lost thirty men. But it encouraged the Benjaminites who had got used to victory and had grown careless. Repetition like this was common in ancient writings, which had listeners in mind.
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.