Midrasch zu Schoftim 20:13

I) But [the children of] Benjamin would not yield (Judges 20:13). The word the children of is missing, for they did an abomination, disgrace, and lewd act in Israel, and they deserve to have their descent from the righteous Benjamin retracted, and to separate them from his generations and inclusions, and they did not call them children of Benjamin for they did not yield to listen to their brothers, and in the remainder of places where they are called children of Benjamin it gave them hope and a path of repentance that they may turn from their evil deeds and repent and be called as their brothers' names the children of Benjamin.