Mundaka-Upanishad: Second Mundaka, Second Khanda
1. Manifest, near, moving in the cave (of the heart) is the great Being. In it everything is centred which ye know as moving, breathing, and blinking, as being and not-being, as adorable, as the best, that is beyond the understanding of creatures.
2. That which is brilliant, smaller than small, that on which the worlds are founded and their inhabitants, that is the indestructible Brahman, that is the breath, speech, mind; that is the true, that is the immortal. That is to be hit. Hit it, O friend!
3. Having taken the Upanishad as the bow, as the great weapon, let him place on it the arrow, sharpened by devotion! Then having drawn it with a thought directed to that which is, hit the mark, O friend, viz. that which is the Indestructible!
4. Om is the bow, the Self is the arrow, Brahman is called its aim. It is to be hit by a man who is not thoughtless; and then, as the arrow (becomes one with the target), he will become one with Brahman.
5. In him the heaven, the earth, and the sky are woven, the mind also with all the senses. Know him alone as the Self, and leave off other words! He is the bridge of the Immortal.
6. He moves about becoming manifold within the heart where the arteries meet, like spokes fastened to the nave. Meditate on the Self as Om! Flail to you, that you may cross beyond (the sea of) darkness!
7. He who understands all and who knows all, he to whom all this glory in the world belongs, the Self, is placed in the ether, in the heavenly city of Brahman (the heart). He assumes the nature of mind, and becomes the guide of the body of the senses. He subsists in food, in close proximity to the heart. The wise who understand this, behold the Immortal which shines forth full of bliss.
8. The fetter of the heart is broken, all doubts are solved, all his works (and their effects) perish when He has been beheld who is high and low (cause and effect).
9. In the highest golden sheath there is the Brahman without passions and without parts. That is pure, that is the light of lights, that is it which they know who know the Self.
10. The sun does not shine there, nor the moon and the stars, nor these lightnings, and much less this fire. When he shines, everything shines after him; by his light all this is lighted.
11. That immortal Brahman is before, that Brahman is behind, that Brahman is right and left. It has gone forth below and above; Brahman alone is all this, it is the best.