As a great buildup to the Dharmakaya as the Nirvanic Kingdom of Self found in the Dharmakaya Sutra, we first need to review The Mahāparinirvāṇasūtra (Nirvana Sutra). When first asked what is meant by Nirvana, The Blessed One responds with Nirvana is what I mean by Liberation. But this is no ordinary liberation. True liberation neither comes into existence nor goes out of existence. This is precisely the Great Liberation of the Tathagata. He does not come into existence, he does not go out of existence, he does not age, he does not die. Thus:
The Buddha’s Parinirvāna can be considered as such: The Buddha’s nirvāṇa— which is referred to in the sūtra as “great nirvāṇa” (mahānirvāṇa) or “great final nirvāṇa” (MAHĀPARINIRVĀṆA)— differs from that of the ARHAT. The nirvāṇa of the arhat is said to be merely the state of the absence of the afflictions (KLEŚA) but with no awareness of the buddhadhātu. The nirvāṇa of the buddha is instead eternal, pure, blissful, and endowed with self, a primordially existent reality that is only temporarily obscured by the kleśa; when that nirvāṇa and buddhadhātu are finally “recognized,” buddhahood is then achieved.
(Buswell Jr., Robert E.; Donald S., Jr. Lopez. The Princeton Dictionary of Buddhism (Kindle Locations 38232-38241). Princeton University Press. Kindle Edition.)
The Tathagata glistens with Deathless Suchness Itself. His own Bodhipower is now attuned at full-peak and securely undivided as to the great significance of his passage into the Nirvanic Kingdom of Self. This is known as the Bliss of Nirvana. This Nirvanic-Kingdom of Self is what constitutes the Dharmakaya—the very Dharma-realm of the Buddhas. Thus, in order to understand the Real Nature of the Tathagata one needs to transcend all nominalized categories and begin to SEE with the Eyes of Liberation, of which the Mahāparinirvāṇasūtra is the Root-Source of such a Dharmatic-Realization. With this Supreme Insight in mind we are now ready to turn to Tozen’s marvelous Dharmakaya Sutra, wherein this great insight is brought to perfection.
The bulk of references to Nirvana occur in the fourth chapter, but chapter one highlights an essential element:
1.3 Thus their knowledge of the self-empty nature of every desire and image in the minds of the suffering was effortless and perfect. Without the slightest self-deception, they saw everything for what it truly was, and was not, in the divided mind of the dreamers. Entirely immersed in that inconceivable dark luminosity that signifies the absoluteness of Nobel Wisdom, their dharma eye effortlessly revealed the true unborn body of the Blessed one. Henceforth their supreme worthiness in this Light of all lights was affirmed and their ability to induce the deathless light of the buddhadharma and thus cause a turn about in the spirit of those with little sand in their eyes, enabled these worthy students of the way to strive towards the inconceivable body of nirvana, and, through the disembodied and wordless transmission of the buddhadharma they proved the suchness of the living principle beyond any reason of a doubt.
This is all made possible through the *Dharma-eye of Perfect Imagelessness*. It’s about having a supraessential perception. Not perception in the conventional understanding of knowing through the senses, but rather a supraessential awareness (Vidya) that is free from all subject-object duality–hence, this is an “imageless” affair. Through this Eye one is able to discern their True Body of Reality—the Dharmakaya.
The following concerns the Fourth Chapter: The wordless transmission of Mahabodhisattva Maitrya.
4.2 Thus fulfilled with the singular supreme will, Mahabodhisattva Maitrya descended from the Tushita Heaven and miraculously appeared before the assembly to further expound on the deathless dharma. The appearance of this great Bodhisattva of Light heralded the Age of the Unborn wherein the final revelation of this dharma-ending age was bestowed: Whosoever awakens to and fully recollects the undivided awareness power of the Unborn Buddha Mind will freely possess the hidden and real nature of Nirvana.
Maitrya’s descent from the Tushita Heavens is an indication that the final revelation of the dharma-ending age (the present age) is at hand…and that is the awakened recollection of the *undivided awareness power of the Unborn Buddha Mind* through which the full meaning of Nirvana is revealed.
4.12“This incomparable truth shines purely as itself in your imageless mind. It is a light of no artificial support and whoever possesses this incomparable light of the imageless mind possesses the invaluable virtue of seeing beyond the deceiving haze of their temporal consciousness, having full view of the shore of nirvana. Indeed such sages recognize their own true family as easily as a child recognizes the face of its true father and mother even in the midst of a great gathering.”
The Truth of the Nirvanic Kingdom of Self can only be known through the imageless mind. All soiled dharmata are filtered through to reveal the undivided Light of the Dharmakaya. This is the only way that the imageless shore of nirvana can be won. Hence, true kinship with the Unborn Mind is an imageless one.
4.23 “To become one with your unborn mind is to become spiritually immersed in the undivided awareness power of your divine body and not lost in the defiled consciousness of the evil one. Being spiritually immersed in the sheer and undivided awareness power of your unborn mind and nothing else, is the very meaning of nirvana.”
A verse pregnant with insight. Nirvana is the self-realization that there is no independent entity that needs salvation from an abstracted and defiled representation that masquerades as apparent existence; nirvana is annihilation of this false no-self representation, thus rendering it extinct. The meaning of nirvana is thus: Annihilation of the false no-self and giving full recollection to the undivided awareness power of the Unborn Mind. Or, Nirvana is the undivided awareness power (bodhi) of the unborn mind that is total and unequivocal, a profound stillness in the raging storm of phenomena; its imageless suchness (tathata) is Nirvana ITself. There is no nirvana outside the full self-recollection that the essence of bodhi is undivided.
4.24 “In the perfect reality of your unborn mind there is nothing but the absolute reality of your permanent body of truth, the dharmakaya; hence its nirvanic nature. Whoever awakes completely with a permanent awareness of the dharmakaya, holding no further residues of a temporal consciousness and its myriad bodies of desire, in spirit and mind, is thus one dwelling in parinirvana.
The nirvanic nature of the Dharmakaya is that there is nothing substantial that “exists” outside the perfect undivided reality of the unborn mind; a permanent *awareness of the Dharmakaya* will supercede any yearning for the *temporal consciousness* as its desire-bodies will be rendered mute. Thus one dwells permanently in *parinirvana*–Mind’s full extinction from the created-sphere of sensate phenomena. This is the only valid explanation of extinction in light of nirvana.
4.29 “Thus the awakened discovers the miracle of the real beholding the real, the pure, undefiled, nirvanic sight of your true nature, and thus their own. Whosoever witnesses and fully abides in this incomparable light of noble wisdom, having spirit and mind purified from its last defilement, will indeed embrace the nirvanic revelation of their true body. The culmination of this is a blazing tenfold ascension towards the self-fulfillment of awakening in the permanent kingdom of their own absolute reality, the dharmakaya.”
This is that True Liberation discussed earlier. There is no other. Noble Wisdom consists in recollecting the nirvanic revelation of one’s True Imageless Body. This is a self-assured Nirvanic Kingdom indeed. It is Being One with the Absolute stamp of the Dharmakaya.