'The old man was too quick for him. He sprang to his feet and leaped to the top of a large rock. There he stood, grown suddenly tall, towering above them. His hood and his grey rags were flung away. His white garments shone. He lifted up his staff, and Gimli's axe leaped from his grasp and fell ringing on the ground. The sword of Aragorn, stiff in his motionless hand, blazed with a sudden fire. Legolas gave a great shout and shot an arrow high into the air: it vanished in a flash of flame.
'Mithrandir!' he cried. 'Mithrandir!''
JRR Tolkien: The Lord of the Rings
: The Two Towers: Book III
, Chapter 5: The White Rider