Chandogya Upanishad 6.16

'My child, they bring a man hither whom they have taken by the hand, and they say: "He has taken something, he has committed a theft." (When he denies, they say), "Heat the hatchet for him." If he committed the theft, then he makes himself to be what he is not. Then the false-minded, having covered his true Self by a falsehood, grasps the heated hatchet—he is burnt, and he is killed.

'But if he did not commit the theft, then he makes himself to be what he is. Then the true-minded, having covered his true Self by truth, grasps the heated hatchet—he is not burnt, and he is delivered. 'As that (truthful) man is not burnt, thus has all that exists its self in That. It is the True. It is the Self, and thou, O Svetaketu, art it.' He understood what he said, yea, he understood it.