Khandogya-Upanishad: First Prapathaka, Seventh Khanda

2. Rik is the eye, Saman the self. This Saman (shadow) rests on that Rik (eye). Therefore the Saman is sung as resting on the Rik. Sa is the eye, ama the self and that makes Sama.

3. Rik is the ear, Saman the mind. This Saman (mind) rests on that Rik (ear). Therefore the Saman is sung as resting on the Rik. Sa is the ear, ama the mind, and that makes Sama.

4. Rik is the white light of the eye, Saman—the blue exceeding darkness. This Saman (darkness) rests on the Rik (brightness). Therefore the Saman is sung as resting on the Rik. Sa is the white light of the eye, ama the blue exceeding darkness, and that makes Sama.

5. Now the person who is seen in the eye, he is Rik, he is Saman, Uktha, Yagus, Brahman. The form of that person (in the eye) is the same, as the form of the other person (in the sun), the joints of the one (Rik and Saman) are the joints of the other, the name of the one (ut) is the name of the other.

6. He is lord of the worlds beneath that (the self in the eye), and of all the wishes of men. Therefore all who sing to the vina (lyre), sing him, and from him also they obtain wealth.

7. He who knowing this sings a Saman, sings to both (the adhidaivata and adhyatma self, the person in the sun and the person in the eye, as one and the same person). He obtains through the one, yea, he obtains the worlds beyond that, and the wishes of the Devas;

8. And he obtains through the other the worlds beneath that, and the wishes of men.

Therefore an Udgatri priest who knows this, may say (to the sacrificer for whom he officiates);

9. “What wish shall I obtain for you by my songs?” For he who knowing this sings a Saman is able to obtain wishes through his song, yea, through his song.