What does Judges 20:4 mean?

In a rare moment during the era of the Judges, eleven of the twelve tribes of Israel have assembled in one place, for one purpose, and in submission to the Lord. They have been united by a shared outrage over an atrocity committed against a concubine (Judges 19:22–27). The nation has been shocked into action by the gruesome distribution of her dismembered body and the story which accompanied it (Judges 19:28–30).

Earlier verses noted that Israel has already amassed troops near Gibeah, where the crime took place (Judges 20:1–3). That implies they have already decided what do. Yet now, with all assembled, the leaders of the eleven tribes call on the Levite man who sent out the severed body parts to officially tell the story. Having this spoken "for the record" will make their response more official.

The Levite is described as the husband of the woman who was murdered. In a literal legal sense, he is the only surviving wronged party. The incredible depravity of the men of Gibeah, though, has elevated events beyond local crime to a matter of national disgrace.

Scripture often leaves out details irrelevant to the story. As far as this account goes, the Levite's version of events is greatly simplified. No mention is made that his concubine had been unfaithful and run away (Judges 19:1–2), that he had gone to reconcile with her (Judges 19:3) and that he had left from Bethlehem too late in the day to make it home before dark (Judges 19:10). This version of the story, or at least what's recorded, is focused on what happened that night in the city of Gibeah.