The Chandogya Upanishad (7.25.1-3)

 The Infinite is below, above, behind, before, to the right, to the left. I am all this. This Infinite is the Self. The Self is below, above, behind, before, to the right, to the left. I am all this. One who knows, meditates upon, and realizes the truth of the Self–such a one delights in the Self, revels in the Self, rejoices in the Self. He becomes master of himself, and master of all the worlds. Slaves are they who know not this truth. He who knows, meditates upon, and realizes this truth of the Self, finds that everything–primal energy, ether, fire, water and all the other elements–mind, will, speech, sacred hymns and scriptures–indeed the whole universe–issues forth from it.