It happened on the next day that the people rose early, and built there an altar, and offered burnt offerings and peace-offerings.
The Israelites’ initial reaction was to ask God to explain the situation (Judges 21:3). The reason for it was their failure to seek and follow God’s will earlier (cf. Judges 20:8-11). Here we see no mourning for sin, no self-humbling because of national transgression, and no return to the Lord. The Lord did not respond to them because they acted in self-will (Judges 21:10).