Japan is a very mountainous country - they say something like only 3% of the land is arable because the rest is covered by steep mountains. Accordingly, mountains figure very prominently in Japanese religion as a place of mystery where subterranean worlds (Japan has a lot of volcanoes) the heavens, and earth meet. The mountain sensibility has been integrated into Japanese Buddhism from early on with mountains becoming special places of practice. One of the most famous mountains, Fuji, has been worshiped as a god since pre-history, and its place in Japanese culture continues to be prominent. Many major Buddhist centers are found in the mountains - Koya-san (Shingon), Hiei-zan (Tendai) - and have integrated mountain ascetic practices into their currucula. Shingon and Tendai both have Yamabushi traditions; the so-called Marathon Monks of Mt. Hiei who perform the Kaihogyo are connected to mountain asceticism.
Enter En-no-gyoja, a semi-mythical figure who was active in the Kii peninsula around Yoshino, South of Nara.
My wife, in preparing for a presentation on Yoshino, showed me the following sutra that is said to have been recorded by En-no-gyoja. Its translated by Paul Swanson (who, in commenting on it, suggests that we can glean a lot about Japanese Buddhism from this. Maybe) Interestingly it appears to deal directly with Original Enlightenment without any mincing nuance. I have reservations about the message from a doctrinal standpoint, but I thought people might find this interesting for its connection to mountain asceticism in Japan as well as Original Enlightenment thought.
Some things I found interesting here: It refers to the encounter with Mahavairocana and "the beginningless and endless original Buddha who is of one mind and one thought" in the innermost chamber. Swanson explains that this may be a reference to the Womb World mandala. I'm not familiar with that practice, but if someone is, it would be interesting to hear some perspective on that. Also, the Buddha King Awesome Sound here is understood to be "the beginningless and endless original Buddha who is of one mind and one thought". King Awesome Sound is understood to be the oldest Buddha referred to in the sutras who is described in the Sadaparibhuta Bodhisattva (Never Disparaging) chapter of the Lotus Sutra. Sadaparibhuta appeared in the Middle Age of King Awesome Sound's dharma teaching.
Swanson explains that "the original Buddha of no mind and no thought" is understood to be reality itself, which in the Mountain Ascetic tradition is the origin from which all wisdom flows. This is translated into practice through the ascetic practices in the mountains that bring us into direct contact with reality, or so I gather.
From "Religions of Japan in Practice":
Sutra on the Unlimited Life of the Threefold Body as Taught by the Buddha
At one time, Bodhisattva Manjusri was seated on a jeweled lotus, having a five-knotted crown on his head, his dark blue hair hanging down to his shoulders, his bodily form that of shing gold, his left [and of] concentration holding a blue lotus with a five pronged Vajra above it, his right [hand of] wisdom grasping a sutra-box [back pack], and his body shining like an autumn rainbow.
Perfectly dwelling in [the state of concentration called] the “moon-ring,” he spoke to the Buddha, saying, “World-Honored-One. We all have, from the distant past, listened to the Tathagata’s preaching of the Dharma. From which Buddha did the Tathagata hear this preaching of the Dharma-sounds?”
The Buddha spoke to Manjusri, saying, “I received the preaching of Mahavairocana after passing through the forty-one levels to enter the great inner chamber.”
The bodhisattva Manjusri again spoke to the Buddha saying, “Who is within the inner chamber of the forty-one levels?”
The World-Honored-One again said, “After passing through the ten stages of abodes, the ten stages of practice, the ten stages of merit-transference, ten bodhisattva stages (bhumi), the stage of becoming comparable to enlightenment and entering the inner chamber, I received the preaching of the Dharma by Mahavairocana, who is at the stage of wonderful enlightenment.”
The bodhisattva Manjusri again spoke to the Buddha, saying, “From what Buddha did Mahavairocana on the stae of wonderful enlightenment receive the preaching of the Dharma?”
The World-Honored-One replied, “Mahavairocana on the stage of wonderful enlightenment received the preaching of the Dharma from the beginningless and endless original Buddha who is of one mind and one thought.”
The bodhisattva Manjusri again spoke to the Buddha saying, “From what Buddha did ‘the beginningless and endless original Buddha who is of one mind and one thought’ receive the preaching of the Dharma?”
The World-Honored-One again said, “’The beginningless and endless original Buddha who is of one mind and one thought’ received the preaching of the Dharma from the original Buddha of no mind and no thought.”
Manjusri again spoke to the Buddha, saying, “From what Buddha did the ‘original Buddha of no mind and no thought’ receive the preaching of the Dharma?”
The World-Honored-One again said, “There is no Buddha above and beyond the ‘original Buddha of no mind and no thought.’ There is no Buddha below and no Buddha after no mind and no thought.’ The original Buddha is in essence beyond conceptual understanding. From the beginning he/it does not go nor come, does not have the nature of the threefold body, does not have the nature of the ten destinies [from hell to Buddhahood.]
Manjusri again spoke to the Buddha, saying, “If above and beyond the original Buddha of no mind and no thought there is no nature of the threefold body and the ten destinies,from what basis do the threefold body and ten destinies arise?”
The World-Honored-One again said, “The original Buddha of no mind and no thought is by nature beyond conceptual understanding. Both the conceptually understood natures of the threefold body and sentient beings in the ten destinies, and the nature of that which is without a nature, arise from the nature that is beyond conceptual understanding.”
Manjusri again spoke to the Buddha, saying, “If this is so, then is there no Buddha who teaches at the beginning?”
The World-Honored-One again said, “There is nothing that teaches or receives above and beyond the original Buddha of no mind and no thought. Moreover, this is a single Buddha, and there are not two Buddhas. You all should shut your eyes and contemplate the original Buddha that is without beginning and without end.”
Manjusri spoke to the Buddha, saying, “That which the World-Honored-One preaches is exceedingly profound. It is true yet beyond our power to comprehend. It is good; it is good. I gladly preach this sutra.”
At that time the Tathagata names King of Imposing Sound [Bhismagarjitasevara-raja] spoke to Manjusri, the prince of the Dharma, saying, “Well done, prince of the Dharma. You have questioned the Tathagata in such a way that it is cause for a great event. Now, listen carefully; listen carefully. Reflect well on these things.”
The Buddha, after preaching this sutra, sat in the lotus position and entered the concentration [Samadhi] that is wonderful and supreme. At that time, Manjusri, prince of the Dharma, and everyone in the assembly of eighty-four thousand monks, all entered the Samadhi through the supranormal power of the Buddha.
The following events were seen. The Buddha, from within his state of concentration, emitted a great circle of light from his own face, illuminating with insight Manjusri and the eighty-four thousand monks. A sword of wisdom [appeared] from the top of Manjusri’s head, and from his side emerged a golden-haired lion. The Tathagata’s ray of light extended everywhere, and the color of his body was like that of gold.
Manjusri spoke to the Buddha, saying, “World-Honored-One. We have attained unprecedented [insight]. Our hearts greatly rejoice.”
The Tathagata again preached in a verse, saying,
The supreme path of all Buddhas
Has the marks of perfect light and eternal abiding.
Those who enter meditative concentration together with [the Buddha]
In the same way realized the mind of enlightenment [bodhicitta].
When the Buddha finished preaching these verses, the great monks in the assembly at once stood up, bowed, and went on their way.