Numbers 32:17

but we ourselves will go ready armed before the children of Israel, they would arm themselves in haste and act as a vanguard of champions before the army of Israel, until we have brought them unto their place, until every tribe has secured its possession; and our little ones shall dwell in the fenced cities because of the inhabitants of the land, for the latter had not been utterly uprooted and annihilated, as had the Midianites.