1 Samuel 17:21

For Israel and the Philistines had put the battle in array, army against army.

Israel and the Philistines had drawn up opposing battle lines, army facing army. The verse occurs as war resumed, with both armies poised for battle when David arrived at Israel's camp. Instead of fighting directly, the Philistines sent Goliath forward to challenge Israel to single combat.

Goliath's taunts terrified Israel's army, while Saul was afraid and unable to lead it with confidence. The standoff sets up David's encounter with Goliath, which shows that God's cause is not won by boastfulness or reliance on human weapons and skill, but by humble trust in God. David's killing of the Philistine champion in this account later made him recognizable and put him in danger when he sought refuge among the Philistines.