On Nirvana

And what is Nirvana? The Master [The Buddha] seldom talked to us of Nirvana. He had no need to do so, for all that met him knew that he had already dwelt in it, and that the utter Nirvana that comes with death would be for him only the completion of a state he already knew. Furthermore, how can Nirvana be described in words when it resembles nothing of earth? All things of earth are composed of different parts or of other things; and they depend for their existence upon each other and upon other things. When they are dissolved, they are separated only to come together, a ceaseless cycle of birth, life, death, and rebirth. Our knowledge of them is gained through our five senses and our intellect which is the sixth sense. Nirvana is not composed of other things, and does not depend upon other things. It is not subject to death or to rebirth. It cannot be known through the six senses, but only with inner sight. It can only be described as “not this” and “not that.” If a turtle were to leave the ocean and seek to describe to a fish the nature of dry land, how should he do it? He would say that dry land is not transparent, neither is it moist nor salty. And yet dry land is, and Nirvana also is. The Master showed us the Way to Nirvana. Yet Nirvana is around us and everything, and in us and everything. It is within this fathom-long body of ours. But we cannot know it in actual experience until we give up the dissolution of being separate selves. Only when the self is extinguished can the True Self be known. This is Nirvana, the going-out of all things of earth, that Amata, the Deathless, may be known.

Yasa  from Footprints of Gautama The Buddha