The children of Israel, i.e. a considerable part of them, who were ordered to give the first onset, and then to counterfeit flight, to draw the Benjamites forth of their strong hold. See Judges 20:32. On the third day, to wit, after the second battle; for the first day after it they spent in perplexing thoughts, and going up to the house of the Lord; the second, in fasting and prayer there; and this third, in the fight. Or this is so called with respect unto the two several foregoing days of battle, and so this was the third day of battle.
Related Commentaries of Judges 20:30
Judges 20:30
30 And the children of Israel went up against the children of Benjamin on the third day, and put themselves in array against Gibeah, as at other times.