C. F. Keil and Franz Delitzsch on Judges 20:23

Jdg 20:23

But before renewing the conflict they went up to Bethel, wept there before Jehovah, i.e., before the sanctuary of the ark, where Jehovah was present in the midst of His people, enthroned between the cherubim, until the evening, and then inquired of the Lord (again through the high priest) “Shall I again draw near to war with the children of Benjamin my brother” (i.e., renew the war with him)? The answer ran thus: “Advance against him.”