‘And the children of Israel went up and wept before Yahweh until even, and asked counsel of Yahweh, saying, “shall I again draw near to battle against the children of Benjamin my brother?” '
Their confidence had been dented, so as well as bringing up reinforcements they again sought God. ‘Went up' suggests that some of their number went again to the central sanctuary at Bethel on their behalf. Or it may be that the Priest was there wearing the ephod and they gathered to the Priest. ‘They wept before Yahweh until evening'. This was partly because of their disastrous defeat, and in mourning for their fallen comrades, but no doubt with great heart searching as to the reasons. Maybe there was also a great searching of their hearts for sins that may have been responsible, including their lack of brotherhood towards Benjamin.
But then they again sought His counsel by Urim and Thummim or by lot (both used a similar method) and their question was whether they should again go up against Benjamin, their ‘brother'. The singular pronouns (compare ‘man of Israel' with a singular verb in Judges 20:20, hidden in translation) demonstrate that they saw themselves as one corporate unit, as ‘Israel', and Benjamin as one unit as well, as their brother. He was a part of them. They, as it were, carried themselves back to their original ancestors, emphasising the family responsibility.
‘And Yahweh said, “Go up against him.”
The lot fell for a further attack on Benjamin. This confirmed for them that Benjamin now shared in the guilt of Gibeah, as well as also being seen as traitors against the covenant and the tribal confederacy. They were thus guilty of sodomy, fornication, murder, and breach of the sacred covenant. Indeed the feeling was so strong that when defeated they would be put to The Ban (Judges 20:48; Judges 21:16), with every man, woman and child being destroyed, as well as cattle. Breach of the covenant was a very serious affair.