Every single character in this chapter is anonymous—the Levite, his concubine, his father-in-law, his servant, the old man, and the worthless fellows of Gibeah. This occurs in a book that often names even its minor characters; see Judges 1:10–11, Judges 4:2, Judges 4:11, Judges 7:10, Judges 7:25, Judges 8:20, and Judges 11:1.1 The namelessness here is telling. It helps this story illustrate the overall point of the book: sin, specifically idolatry, dethroning God and putting created things in his place, leads to misery, chaos, immorality, dehumanization, and destruction. The absence of names also universalizes things; it gives the impression that every person within Israel was doing right in his own eyes, every host was capable of the crimes of the Benjamites, and every guest, concubine, and woman from Dan to Beersheba could be denied personhood, raped, murdered, and dismembered.2
1 In those days, when there was no king in Israel, a certain Levite was sojourning in the remote parts of the hill country of Ephraim, who took to himself a concubine from Bethlehem in Judah.