the seer, though unseen

.

...the Imperishable.  It is neither big nor small, neither long nor short,
 neither hot nor cold, neither bright nor dark, neither air nor space. 
 It is without attachment, without taste, smell, or touch, without eyes, ears, 
tongue, mouth, breath, or mind, without movement, without limitation,
without inside or outside.  It consumes nothing, and nothing consumes it.

In perfect accord with the will of the Imperishable, sun and moon make their orbits;
 heaven and earth remain in place; moments, hours, days, nights, fortnights, 
months, and seasons become years; river starting from the snow-clad mountains 
flow east and west, north and south, to the sea.

Without knowing the Imperishable, whoever performs rites and ceremonies
 and undergoes austerities, even for many years, reaps little benefit,
 because rites, ceremonies, and austerities are all perishable.  Whosoever dies 
without knowing the Imperishable dies in a pitiable state; but those who know 
the Imperishable attain immortality when the body is shed at death.

The Imperishable is the seer, though unseen; the hearer, though unheard;
 the thinker, though unthought; the knower, though unknown. Nothing 
other than the Imperishable can see, hear, think, or know.  It is in
 the Imperishable that space is woven, warp and woof.

~  from the Brihadaranyaka Upanishad

translated by Eknath Easwaran