The beginning of one’s sadhana  is endorsed by Chhandogya Up with the declaration -
 - Here in this city of Brahman is an abode, a small lotus flower within which is a small space. What is within that space is what one should seek, for that is what one should desire to understand. Yajnavalkya identifies the Self as he who breathes in when one breathes in, breathes out, breathes breathes  about, breathes up,

and further says that he is the Person,wise enlightened in consciousness,luminous in the heart,

who is to be known even when one is here in this life –

Even though Krishna has commended that one should seek enlightenment through one’s own intense austerity and perfected penance – Katha Up. qualifies saying that the supreme Self is not within the filed of vision no one being able to see him with (gross physical) eye and only by heart, intellect and the mind can he be apprehended -
Shankara clarifies the eye stands for the sense organs –. When Upanishad says the supreme Self is to be apprehended the suggestion is to be in the state of yoga, making the five senses, together with mind cease from their normal – empirical – activities and the intellect itself not stir –

it is the beginning of the  procedure which Yajnavalkya lays down in Brihad Aranyaka Up. to access  the Self within - 

Kena Up, cautions that whatever is uttered as speech - , what is thought by mind - , what is seen by eyes - , what is heard by ears - what is initiated by breath  -
here is not the Self.
  It is other than the known and is above the unknown – .
When Upanishad says the supreme Self is to be apprehended Yajnavalkya’s suggestion that the Self is to be searched within being receptive, reflective and meditative -
comes out as the step in furtherance of the statement in Katha Up. the state of yoga, making the five senses, together with mind cease from their normal – empirical – activities and the intellect itself not stir –

The upanishdic statement appears more elaborated in Zen Buddhism which keeps more emphasis on receptivity, where enlightenment does come as some thing given by others but as some thing taken. Knowledge is a barrier between ignorance and enlightened Wisdom. Therefore Wisdom is being disconnected with all that one has been taught, communicated as philosophy, as belief, as faith, as religion with all the personalized and organizational structure which one has been built to communicate, to organize, to crystallize to promote a belief and a faith than a perception, experience of , the Prime Existence expressed as philosophy.

Mind is a clear mirror which has gathered dust. There is nothing wrong with the mirror, it is the dust on the mirror that distorts the view. In the language of Zen Buddhishsm, ‘The mirror is thoroughly egoless and mindless… There is no discriminating mind or self consciousness on the part of the mirror. If something comes, the mirror reflects; if it disappears the mirror just lets it disappear’. ‘The Tao is something blurred and indistinct. How indistinct !  How blurred ! Yet within it are images . . . things . . . mental power. Because this power is the most true within it there is confidence’.

No mirror is dusty or clean. Diversity and distinctions are product of the I-sense. It is the dust that makes it appear dirty. If you are irritated by every rub, how will your mirror be polished.The mirror whose face is dirty needs to be cleansed. Only when cleansed will the mirror become thoroughly egoless reflect in its own purity and clarity. Nothingness of dust is the state of Yoga referred by Kath Up. -
.Francis Bacon said that ‘Philosophy directs us first to seek the good of the mind, and the rest will either be supplied or not much wanted’.

Philosophy in its true sense is the love for enlightened Wisdom. Knowledge is comparable with other knowledge; it is Wisdom which is distinctive and unique. One can know only that which is known by others earlier.  It will be seen from whatever philosophies one read much of what is written therein has already been written by some others as well, same thing repeated again and again, only the words, terms, definitions and phrases changing with people, places and periods. A lay seeker as well as an adept responds the same manner when he encounters the old texts, what has been said therein having been experienced faintly and inconclusively some earlier moment in Time some where earlier place. Even a great seer like Ramana Maharshi when he glanced through some of the scriptures handed over to me said to himself ‘ … as I listened to the Ribhu Gita and other sacred books, I learnt all this and found that they were analyzing and naming what I had felt intuitively without analyzing and naming’.

Unique means incomparable existence beyond knowing and Knowledge. Wisdom alone is unique. , the Prime Existence alone is incomparable since there was nothing else that can be compared or known except as Wisdom, which neither non-Existence nor Existence IS –
therefore enlightened awareness of that alone as Wisdom is Unique. No one is aware of what , the Prime Existence as something as known, as something taught, as some thing communicated as philosophy, as belief, as faith, as religion  all ideas, opinions, concepts and conclusion being fixed as dead and not as living,  moving, energetic and volatile. Because , the Prime Existence existed even before mind, thinking, ideas, opinions and concepts came to exist. Thinking, ideas, opinions and concepts were not original but come as screens, the reflections one finds in mind.

Philosophy is consequential and not original. Therefore philosophy does not reveal , the Prime Existence but is possible to reflect only ion a mind which is not as ideas, opinions, concepts and thoughts. , the Prime Existence  is pure, unhampered by any idea, opinion, concept and thought therefore, , the Prime Existence is possible to be accessed only when the mind is free of ideas, opinions, concepts and thoughts. MaitriUp. Points out

Krishna’s attempt to communicate Arjuna did not appear to have succeeded as when traditional anthropological and pictographic description did not satisfy his curiosity desiring to see his resplendence –
as if in aknowledgement of the upanishdic statement that not by much speaking nor by much intelligence not even by much hearing but only when the Self itself reveals its form  - 
the Prime Existence is no a theorem, an idea proposed and accepted as true; liker love it is an experience to be experienced. In mathematics and physics there are  theorems and theories. Spiritual enlightenment is an experience and not a theory. Intekkect and intelligence are only means and not the end. Krishna knows that neither words can communicate the divine resplendence nor human empirical eyes can acvcess it . Therefore Krishna offers him spiritual eye saying –

Sanskrit is a very meticulous language. The words used normally and especially in scriptures contain many mystical truths. Maitri Up points out that there two forms of Brahman, - the spoken one and the one beyond and the one who knows the reaches the one beyond. One becomes enlightened of , the Prime Existence, wherein everything is united as warp and woof and wherefrom everything else emanates, as creation -  

Brihad Aranyak Up. and Mundaka Up. describes the vedic scriptures and other subsidiary texts as clouds of smoke issuing forth from That One as a lighted fire would issue forth from damp fuel -
not the author of the hymns. They are known as because they were seen,
because they were heard reveled and experienced through mediation and action - by different seers, during different periods, in different places and expressed in mystical language without human effort. They are known as because they conceal – Therefore ‘seeing’ it is not seen, hearing it is not heard. But for another one, it reveals its noble form, as a loving wife would reveal her form to her husband -

It is said further,

When it was desired that objects be assigned with names, Vak came to be sent as the earliest of all utterances, through Braihaspati, the first and the foremost. Vak the Speech, which was best and stainless, was revealed, along with its divine mystery -
Then they separated and classified – It came to be classified in four groups, all of which the men of Wisdom are aware of. In the first three groups are hidden the mystical secrets and men speak only in the fourth classification –
For the human beings derived from with the proposition and   became and for
Through words, terms and figures used by Seers, one substratum of all that is communicated is maintained by them,somegiving voice to rich, subtle and profound while others may in language which is ordinary and conventional in sense providing  ‘. . . the same firm foundation of knowledge and the same scrupulous adherence to the sacred conventions of the Initiates” as pointed out by Sri Aurobindo.

is pure existence, silent in existence as the Prime Existence. It is state of Silence which the master of the meditation experiences. Patanjala Yoga refers it as - When the agitations of the mind are under control, the mind becomes like a transparent crystal and has the power of becoming whatever form is presented. knower, act of knowing, or what is known and   The subtle terminates having no distinguishing mark. As thoughts become rare and subtle, the mind subsides and eventually ceasing all association with thoughts – is the most subtle objectification state, but it is not yet devoid of subtlety. It is not yet the state of Samadhi, where there exist no objects of thought. Consciousness without thoughts is Samadhi. Consciousness is what exists as potential and not as actual. Consciousness is the seed which becomes the plant and feels the breeze which was also the product of the same seed. Consciousness is the formless unconditioned nature beyond the memory of thoughts which approximates emptiness of mind but not the emptiness or nothingness but one which does not have any identification or distinguishing mark. Nothing comes in the grasp of  the intellect in this Samadhi, it is felt as Consciousness alone which is experienced as the static formless non-dual. Pleasure or pain, righteousness or non-righteousness, merit or demerit, virtue or vice that are pair of opposites and duality reflection -all becomes meaningless. In this state  the conscious mind is fixed on the inner experience, mind, self-sense getting eliminated.   Nothing is experienced all reality getting eliminated, with  no thought and no experience.

The Prime Existence was there before Existence came to be created. Existence therefore, it is known as the Prime Existence. What is created also comes to destruction. is eternal essence it is not born with the form,   nor does it cease with forms . Yama communicates to Nachiketa which was spoken in vedic scriptures, which austerities declares and desiring which those who live intent of Brahman.  the Silent sound – was not born nor does it die. Sound can be created but not the Silence. Silence was there before Vak could be vocal. Its essence is the Prime Existence its form is the Word. Vak comes and goes but Silence continues. is the foundation language is the mansion built thereon.

Thinking is stimulating the Sound, the Vak. Meditation is soothing the sound of the thoughts. Therefore, meditation begins with the Silent sound – , not with , speech. means one which is stationary not mobile, some thing which is not born, some thing like unspoken sound, which becomes spoken sound when there is impulse, movement a flow. Bodhidharma described Zen as: ‘Not reliant on the written word. A special transmission separate from the scriptures; Direct pointing at one's mind, Seeing one's nature, becoming a Buddha’. ‘The Tao that can be told is not the eternal Tao; The name that can be named is not the eternal name’. The least movement is of importance to all nature. The entire ocean is affected by a pebble says Blaise Pascal.

An empirical mind thinks on the basis what he already knows. He will hear the same sounds reverberating in mind again and again, even as the same forms flash on his mind. The meditative mind does not think, all thoughts having been removed from mind, being receptive to Silent sound – and not to speech the spoken word. Meditation begins when mind is made silent emptied of the Knowledge one knows. When one is in empirical state one hears only that which is heard, all the spoken words. The sensitive seers ‘saw’ therefore are called and ‘heard’ therefore  hymns are called as

Therefore Yajnavalkya says
means seeing as one would see an amalakaa fruit on the palm of his hand. means listening receptively not hearing sounds mechanically. Listening is hearing the silent sound – with mind, not cluttered with thinking, ideas, opinions and concepts thoughts, opinions and views all that one has been taught, communicated as philosophy, as belief, as faith, as religion. When mind is silent then it becomes receptive listening the unspoken words and unheard  silent sound – is the greate refuge for seekers of the Prime Existence.

   is being receptive to the unspoken words and unheard  silent sound – . This is what Aruni seeing his son Shevtaketu becoming proud of being learned in vedic wisdom, asked him whether he has received instruction by which unherable becomes heard, the unperceivable becomes perceived, and the unknowable becomes known- then seeing that he has not impart the same enjoining him during the course of instruction to become receptive to what he is communicating –

Shankara says that although a meaning of the mystical truths could be arrived through scriptures, logic and rational reasoning still in the absence of unhindered receptive mind it is very difficult for a mind influenced by sensory organs to comprehensively assimilate the mystical meanings. When mind is receptive it becomes firmly established on the subject matter to be reflected and meditated –
Therefore, Svetaketu needs to be receptive - . Shankara explains which normally people use as faith or belief having understood the word erroneously. is acceptance having enlightened receptivity that the gross world pf perception possessed of and is born from the subtle Existence though  through logic and scriptural statements the meaning is arrived, in the absence of complete receptivity it is very difficult for mind, which is engrossed on material things influenced by senses  and impelled by natural inclinations to comprehend the subtle things. Word does not give Wisdom it provides only Knowledge as the intermediate medium. Therefore, through Knowledge howsoever gathered and remembered does not give one access to the Prime Existence, even as the knowledge of the formule and constituents of Water would not quench one’s thirst for water.  It is easier to gather Knowledge which is nothing but information gathered, but difficult to be wise in Wisdom.  Shankara enjoins Eawa, because where one is receptive his mind becomes concentrated on the things to be understood and comprehension becomes easy. This he says becomes clear from statements like ‘my mind was elsewhere’ –

A seed is no more than a flower in disguise. A seed can not determine how it would unfold. It is only receptive to the divine energy within to shape the unfolding. It is only when mind that becomes unconditionally receptive to the unspoken words and unheard silent sound – that it listens what the word suggests making mind capable of meditation. is meditation.  A mind that meditates is concerned only with meditation and not with the meditator or not concerned with reaching out, gaining, achieving, experiencing. Meditation is difficult which can neither be taught nor learnt. It has no technique and therefore no authority. It is being one own self. Zen masters described it variously as ‘Sitting quietly, doping nothing, spring comes and thee grass grows by itself’, ‘You cannot get it by taking thought; you cannot seek it by not taking thought’. ‘At one strike I forgot all my knowledge ! There is no use for artificial discipline, for, move as I will, I manifest the ancient Way’.

Mediation begins even as one observes intently a dry leaf fall from tree being tossed by the breeze hither and thither till it comes to rest gently on the ground below. It is observing and watching similarly oneself as one lifts one’s legs as one walks, watching how the first foot follows the foot that was placed earlier. Observe oneself as one eats, when one gossips, is jealous, hates, being aware of all that as you yourself, without any choice, without preference without judgment and one will realize oneself going in  meditative mood.. What does one get from such meditation. Perhaps nothing and if one gets some thing  that would be that which one desired conceptualizing as something thought based from Knowledge of what one earlier had knowledge.

When Enlightenment comes like lightening all of sudden and not slowly then you becomes aware of all that is in a moment, in a fraction as lightening all become clearly seen in that very moment and not in stages. Nature abhors a vacuum, even if  one exists without speaking one is sufficiently filled silence. Enlightenment is an infinite of which the center is everywhere and the circumference nowhere. Every one becomes enlightened every moment of one’s life. But one is not be able to recognize when enlightenment comes because it is not an empirical experience, the product of an empirical mind. In enlightenment all dualities are dropped, nothing high or low, nothing good or bad, nothing auspicious or inauspicious all become one because existence is one, all joined and all united.  Zen masters described it variously as ‘Fire does not wait for the Sun to be hot; nor the wind for the Moon to be cool’, ‘The blue mountains are of themselves blue mountains; The white clouds are of themselves white clouds’, ‘In the landscape of the spring there is neither high nor low; The flowering branches grow naturally , some long and some short’,  ‘When the name is uttered neither Buddha nor the self. There is The Voice alone is heard’.

It is beyond the grasp of core nature essence or conscious mind state of nature essence. One can say that inner God essence is trying to visualize himself by himself. Such is the glimpse like vision. It is then that having a glimpse like feeling; of the visions of God essence becomes meaningless. Even search for supreme spiritual knowledge becomes meaningless. It is the state which Brihad Aranya Up. describes that as the highest goal, highest treasure, highest world, greatest bliss, on a particle of which all creatures live –
This state is said to be That, indeed, is the state which Aruni exhorted his son when he said being receptive to what one is  through seeing, listening, reflecting culminating in being