Even before the Buddha's parinirvāṇa, the term Dhammakāya was current. Dhammakāya literally means Truth body. In the Pāli Canon, Gautama Buddha tells Vasettha that the Tathāgata is the Dhammakāya, the 'Truth-body' or the 'Embodiment of Truth', as well as Dhammabhūta, 'Truth-become', 'One who has become Truth.' The Buddha is equated with the Dhamma: "he Buddha comforts him, 'Enough, Vakkali. Why do you want to see this filthy body? Whoever sees the Dhamma sees me; whoever sees me sees the Dhamma.'" In the Aggañña Sutta, the Buddha advises Vasettha that whoever has strong, deep-rooted, and established belief in the Tathagata can declare that he is the child of Bhagavan, born from the mouth of Dhamma, created from Dhamma, and the heir of Dhamma. Because the titles of the Tathagatha are: The Body of Dhamma, The Body of Brahma, the Manifestation of Dhamma, and the Manifestation of Brahma.
Mahāyāna
The Dharmakāya doctrine was possibly first expounded in the Aṣṭasāhasrikā Prajñāpāramitā "The Perfection of Wisdom In Eight Thousand Verses", composed in the 1st century BCE.. Mahayana Buddhism introduced the Sambhogakāya, which conceptually fits between the Nirmāṇakāya and the Dharmakaya. The Sambhogakaya is that aspect of the Buddha, or the Dharma, that one meets in visions and in deep meditation. It could be considered an interface with the Dharmakaya. The Trikaya-doctrine and the Buddha-nature bring the transcendental within reach, by placing the transcendental within the plane of immanence. Around 300 CE, the Yogacara school systematized the prevalent ideas on the nature of the Buddha in the Trikaya or three-body doctrine.
Interpretation in Buddhist traditions
Schools have different ideas about what the three bodies are.
The Nirmaṇakāya is a physical/manifest body of a Buddha. An example would be Gautama Buddha's body.
The Sambhogakāya is the reward/enjoyment body, whereby a bodhisattva completes his vows and becomes a Buddha. Amitābha, Vajrasattva and Manjushri are examples of Buddhas with the Sambhogakaya body.
The Dharmakāya is the embodiment of the truth itself, and it is commonly seen as transcending the forms of physical and spiritual bodies. Vairocana Buddha is often depicted as the Dharmakāya, particularly in esoteric Buddhist schools such as Shingon Buddhism, Tendai and Kegon in Japan.
As with earlier Buddhist thought, all three forms of the Buddha teach the same Dharma, but take on different forms to expound the truth.
Chan Buddhism
According to Schloegl, in the Zhenzhou Linji Huizhao Chansi Yulu, the Three Bodies of the Buddha are not taken as absolute. They would be "mental configurations" that "are merely names or props" and would only perform a role of light and shadow of the mind. The Zhenzhou Linji Huizhao Chansi Yulu advises:
Fourth and Fifth Bodies - Svābhāvikakāya and Mahasukhakaya
sometimes refers to a fourth body called the svābhāvikakāya "essential body", and to a fifth body, called the mahāsūkhakāya. The svābhāvikakāya is simply the unity or non-separateness of the three kayas. The term is also known in Gelug teachings, where it is one of the assumed two aspects of the dharmakāya: svābhāvikakāya "essence body" and jñānakāya "body of wisdom". Haribhadra claims that the Abhisamayalankara describes Buddhahood through four kāyas in chapter 8: svābhāvikakāya, dharmakāya, sambhogakāya and nirmāṇakāya.
Dzogchen
In dzogchen teachings, "dharmakaya" means the buddha-nature's absence of self-nature, that is, its emptiness of a conceptualizable essence, its cognizance or clarity is the sambhogakaya, and the fact that its capacity is 'suffused with self-existing awareness' is the nirmanakaya.
The interpretation in Mahamudra is similar: When the mahamudra practices come to fruition, one sees that the mind and all phenomena are fundamentally empty of any identity; this emptiness is called dharmakāya. One perceives that the essence of mind is empty, but that it also has a potentiality that takes the form of luminosity. In Mahamudra thought, Sambhogakāya is understood to be this luminosity. Nirmanakāya is understood to be the powerful force with which the potentiality affects living beings.
In the view of Anuyoga, the Mind Stream is the 'continuity' that links the Trikaya. The Trikāya, as a triune, is symbolised by the Gankyil.
Dakinis
A ḍākinī is a tantricdeity described as a female embodiment of enlightened energy. The Sanskrit term is likely related to the term for drumming, while the Tibetan term means "sky goer" and may have originated in the Sanskrit khecara, a term from the Cakrasaṃvara Tantra. Ḍākinīs can also be classified according to the trikāya theory. The dharmakāya ḍākinī, which is Samantabhadrī, represents the dharmadhatu where all phenomena appear. The sambhogakāya ḍākinī are the yidams used as meditational deities for tantric practice. The nirmanakaya ḍākinīs are human women born with special potentialities; these are realized yogini, the consorts of the gurus, or even all women in general as they may be classified into the families of the Five Tathagatas.
Non-Buddhist Interpretations
Theosophy
, a Western esoteric school founded in the 19th century, regards Buddhism as containing esoteric teachings. In those supposed esoteric teachings of Buddhism, "exoteric Buddhism" believes that Nirmanakaya simply means the physical body of Buddha. According to the esoteric interpretation, when the Buddha dies, he assumes the Nirmanakaya instead of going into Nirvana. He remains in that glorious body he has woven for himself, invisible to uninitiated mankind, to watch over and protect it.
