the Unknowability of Brahman

Brihadaranyaka Upanishad, Chapter 3, Fourth Brahmana

(from: http://www.swami-krishnananda.org/brdup_audio/brdup-17.pdf )

 

He who breathes in through the Prana is your inner Self.
He who performs the function of expiration is your own Self
   that is working in the form of this outward breath, the Apana.
That which pervades your whole body, known as Vyana,
   again, is the operation of your own Self.
That which works as Udana, whose activity consists of lifting the body at the time of death
   and performing certain other functions of that nature,
   that which is called Udana in ordinary language, is really your own Self that is working.

There is no such thing as Prana, Apana, Vyana, Udana, Samana.
They are only names that we give to the functions of the inner Self that is yours.

You tell me that I have to point out the Self as if it is a cow or a horse.
Not possible!

It is not an object like a horse or a cow.
I cannot say, "here is the Atman; here is the Self".
It is not possible because:
   Na drster drastaram pasyeh- you cannot see the Seer of seeing.
The seer can see that which is other than the seer, or the act of seeing.
An object outside the seer can be beheld by the seer.
How can the seer see himself? How is it possible?
   Na drster drastaram pasyeh: You cannot see the seer of seeing.
   Na sruter srotaram srnuyah: You cannot hear the hearer of hearing.
   Na mater mantaram manvithah: You cannot think the Thinker of thinking.
   Na vijnater vijnataram vijaniyah: You cannot understand the Understander of understanding.
   Esa ta atma sarvantarah: That is the Atman.