15 When the servant of the man of God got up and went out early the next morning, an army with horses and chariots had surrounded the city. “Oh no, my lord! What shall we do?” the servant asked.
16 “Don’t be afraid,” the prophet answered. “Those who are with us are more than those who are with them.”
17 And Elisha prayed, “Open his eyes, LORD, so that he may see.” Then the LORD opened the servant’s eyes, and he looked and saw the hills full of horses and chariots of fire all around Elisha.

References for 2 Kings 6:17

18 As the enemy came down toward him, Elisha prayed to the LORD, “Strike this army with blindness.” So he struck them with blindness, as Elisha had asked.

References for 2 Kings 6:18