At harvest-time, the Three, who were part of the Thirty leading warriors, went down to meet David when he was at the cave of Adullam. The Philistine army was camped in the valley of Rephaim.
It will look as empty as fields after reapers have harvested the grain, gathering up the grain in their arms. It will be like when people pick the heads of grain in the Valley of Rephaim.