Prajapati said to them: The person that is seen in the eye-that is the Self. He further said: This is immortal, fearless. This is Brahman. They asked: Venerable Sir, he who is perceived in the water and he who is perceived in a mirror-which of these is he? Prajapati replied: The same one, indeed, is perceived in all these.

Sama Veda, Chandogya Upanishad VIII, VII - The Person in the Eye, 4

Prajapati said: Look at yourself in a pan of water and then what you do not understand of the Self come and tell me. They cast their glance in a pan of water. Then Prajapati said to them: What do you see? They said: Venerable Sir, we see the entire self even to the very hairs and nails, a veritable picture.

Sama Veda, Chandogya Upanishad VIII, VIII - The Doctrine of the Demons, 1

Prajapati saw them going and said: They are both going away without having known and without having realized the Self. And whoever of these, whether gods or demons, follow this doctrine shall perish. Virochana, satisfied in heart, went to the demons and preached this doctrine (Upanishad) to them: The self (i.e. body) alone is to be worshipped here on earth, the self (i.e. body) alone is to be served. It is only by worshipping the self here and by serving the self that one gains both worlds-this and the next.

Sama Veda, Chandogya Upanishad VIII, VIII - The Doctrine of the Demons, 4

Of this being who is in the solar orb, the syllable Bhuh is the head, for there is one head and there is this one syllable; the word Bhuvah is the arms, for there are two arms and there are these two syllables; the word Svah is the legs, for there are two legs and there are these two syllables. His secret name is Ahar. He who knows this destroys evil and leaves it behind.

Yajur Veda, Brihadaranyaka Upanishad V, V-In Praise of Satya Brahman, 3

Of this being who is in the right eye, the syllable Bhur is the head, for there is one head and there is this one syllable; the word Bhuvar is the arms, for there are two arms and there are these two syllables; the word Svar is the legs, for there are two legs and there are these two syllables. His secret name is Aham. He who knows this destroys evil and leaves it behind.

Yajur Veda, Brihadaranyaka Upanishad V, V-In Praise of Satya Brahman, 4