Kukai the Grand Master

Kūkai (空海), also known posthumously as Kōbō-Daishi (弘法大師 The Grand Master Who Propagated the Buddhist Teaching), 774–835, was a Japanese Buddhist monk, civil servant, scholar, poet, and artist who founded the Shingon or "True Word" school of Buddhism. Shingon followers usually refer to him by the honorific title of Odaishisama (お大師様) and the religious name of Henjō-Kongō (遍照金剛).

Kūkai is famous as a calligrapher and engineer. Among the many achievements attributed to him is the invention of the kana, the syllabary with which, in combination with Chinese characters (kanji), the Japanese language is written to this day. Also according to tradition, the Iroha, which uses every phonetic kana syllable just once and is one of the most famous poems in Japanese, is attributed to him but again, this is a popular belief and nowhere attested to. His religious writings, some fifty works, expound the Esoteric Shingon doctrine. The major ones have been translated into English by Yoshito Hakeda (see references below).

空海(くうかい、宝亀5年(774年) - 承和2年3月21日(835年4月22日))は、平安時代初期の僧。弘法大師(こうぼうだいし)の諡号(921年、醍醐天皇による)で知られる真言宗の開祖である。俗名(幼名)は佐伯 眞魚(さえき の まお[1])。日本天台宗の開祖最澄(伝教大師)と共に、日本仏教の大勢が、今日称される奈良仏教から平安仏教へと、転換していく流れの劈頭に位置し、中国より真言密教をもたらした。能書家としても知られ、嵯峨天皇・橘逸勢と共に三筆のひとりに数えられている。

Early years[edit]

Painting of Kūkai as a childWood statue of Kūkai.

Kūkai was born in 774 in the present-day Zentsū-ji precincts in the province of Sanuki on the island of Shikoku. His family were members of the aristocratic Saeki family, a branch of the ancient Ōtomo clan. There is some doubt as to his birth name: Tōtomono (precious one) is recorded in one source, while Mao (True Fish) is recorded elsewhere. Mao is generally used in modern studies.[1] Kūkai was born in a period of important political changes with Emperor Kanmu (r. 781–806) seeking to consolidate his power and to extend his realm, taking measures which included moving the capital of Japan from Nara ultimately to Heian(modern-day Kyoto).

Little more is known about Kūkai's childhood. At the age of fifteen, he began to receive instruction in the Chinese classics under the guidance of his maternal uncle. During this time, the Saeki-Ōtomo clan suffered government persecution due to allegations that the clan chief, Ōtomo Yakamochi, was responsible for the assassination of his rival Fujiwara no Tanetsugu.[1] The family fortunes had fallen by 791 when Kūkai journeyed to Nara, the capital at the time, to study at the government university, the Daigakuryō (大学寮). Graduates were typically chosen for prestigious positions as bureaucrats. Biographies of Kūkai suggest that he became disillusioned with his Confucian studies, but developed a strong interest in Buddhist studies instead.

Around the age of 22, Kūkai was introduced to Buddhist practice involving chanting the mantra of the Bodhisattva Ākāśagarbha (Kokuzō). During this period, Kūkai frequently sought out isolated mountain regions where he chanted the Ākāśagarbha mantra relentlessly. At age 24 he published his first major literary work, Sangō Shiiki, in which he quotes from an extensive list of sources, including the classics of Confucianism, Daoism, and Buddhism. The Nara temples, with their extensive libraries, possessed these texts.

During this period in Japanese history, the central government closely regulated Buddhism through the Sōgō (僧綱, Office of Priestly Affairs) and enforced its policies, based on the ritsuryō system. Ascetics and independent monks, like Kūkai, were frequently banned and lived outside the law, but still wandered the countryside or from temple to temple.[2]

During this period of private Buddhist practice, Kūkai had a dream, in which a man appeared and told Kūkai that the Mahavairocana Tantra is the scripture which contained the doctrine Kūkai was seeking.[1] Though Kūkai soon managed to obtain a copy of this sūtra which had only recently become available in Japan, he immediately encountered difficulty. Much of the sūtra was in untranslated Sanskrit written in the Siddhaṃ script. Kūkai found the translated portion of the sūtra was very cryptic. Because Kūkai could find no one who could elucidate the text for him, he resolved to go to China to study the text there. Ryuichi Abe suggests that the Mahavairocana Tantra bridged the gap between his interest in the practice of religious exercises and the doctrinal knowledge acquired through his studies.[2]











Travel and study in China[edit]

Kōbō Daishi altar at Tian Hou Temple, Taipei.

In 804 Kūkai took part in a government-sponsored expedition to China in order to learn more about the Mahavairocana Tantra. Scholars are unsure why Kūkai was selected to take part in an official mission to China, given his background as a private, not state-sponsored, monk. Theories include family connections within the Saeki-Ōtomo clan, or connections through fellow clergy or a member of the Fujiwara clan.[1]

The expedition included four ships, with Kūkai on the first ship, while another famous monk, Saichō was on the second ship. During a storm, the third ship turned back, while the fourth ship was lost at sea. Kūkai's ship arrived weeks later in the province of Fujian and its passengers were initially denied entry to the port while the ship was impounded. Kūkai, being fluent in Chinese, wrote a letter to the governor of the province explaining their situation.[3] The governor allowed the ship to dock, and the party was asked to proceed to the capital of Chang'an (present day Xi'an), the seat of power of the Tang dynasty.

After further delays, the Tang court granted Kūkai a place in Xi Ming Temple where his study of Chinese Buddhism began in earnest as well as studies of Sanskrit with the Gandharan pandit Prajñā (734-810?) who had been educated at the Indian Buddhist university at Nalanda.

It was in 805 that Kūkai finally met Master Huiguo (746 – 805) the man who would initiate him into the esoteric Buddhism tradition at Chang'an's Qinglong Monastery (青龍寺). Huiguo came from an illustrious lineage of Buddhist masters, famed especially for translating Sanskrit texts into Chinese, including the Mahavairocana Tantra. Kūkai describes their first meeting:

Accompanied by Jiming, Tansheng, and several other Dharma masters from the Ximing monastery, I went to visit him [Huiguo] and was granted an audience. As soon as he saw me, the abbot smiled, and said with delight, "since learning of your arrival, I have waited anxiously. How excellent, how excellent that we have met today at last! My life is ending soon, and yet I have no more disciples to whom to transmit the Dharma. Prepare without delay the offerings of incense and flowers for your entry into the abhisheka mandala".[2]

Huiguo immediately bestowed upon Kūkai the first level abhisheka (esoteric initiation). Whereas Kūkai had expected to spend 20 years studying in China, in a few short months he was to receive the final initiation, and become a master of the esoteric lineage. Huiguo was said to have described teaching Kūkai as like "pouring water from one vase into another".[2] Huiguo died shortly afterwards, but not before instructing Kūkai to return to Japan and spread the esoteric teachings there, assuring him that other disciples would carry on his work in China.

Kūkai arrived back in Japan in 806 as the eighth Patriarch of Esoteric Buddhism, having learnt Sanskrit and its Siddhaṃ script, studied Indian Buddhism, as well as having studied the arts of Chinese calligraphy and poetry, all with recognized masters. He also arrived with a large number of texts, many of which were new to Japan and were esoteric in character, as well as several texts on the Sanskrit language and the Siddhaṃ script.

However, in Kūkai's absence Emperor Kanmu had died and was replaced by Emperor Heizei who exhibited no great enthusiasm for Buddhism. Kukai's return from China was eclipsed by Saichō, the founder of the Tendai school, who found favor with the court during this time. Saichō had already had esoteric rites officially recognised by the court as an integral part of Tendai, and had already performed the abhisheka, or initiatory ritual, for the court by the time Kūkai returned to Japan. Later, with Emperor Kanmu's death, Saichō's fortunes began to wane.

Saichō requested, in 812, that Kūkai give him the introductory initiation, which Kūkai agreed to do. He also granted a second-level initiation upon Saichō, but refused to bestow the final initiation (which would have qualified Saichō as a master of esoteric Buddhism) because Saichō had not completed the required studies, leading to a falling out between the two that was not resolved; this feud later extended to the Shingon and Tendai sects.

Little is known about Kūkai's movements until 809 when the court finally responded to Kūkai's report on his studies, which also contained an inventory of the texts and other objects he had brought with him, and a petition for state support to establish the new esoteric Buddhism in Japan. That document, the Catalogue of Imported Items, is the first attempt by Kūkai to distinguish the new form of Buddhism from that already practiced in Japan. The court's response was an order to reside in the Takaosan (later Jingo-ji) Temple in the suburbs of Kyoto. This was to be Kūkai's headquarters for the next 14 years. The year 809 also saw the retirement of Heizei due to illness and the succession of the Emperor Saga, who supported Kūkai and exchanged poems and other gifts.




同年5月12日、難波津を出航、博多を経由し7月6日、肥前国松浦郡田浦、五島市三井楽町[8] から入唐の途についた。空海と橘逸勢が乗船したのは遣唐大使の乗る第1船、最澄は第2船である。この入唐船団の第3船、第4船は遭難し、唐にたどり着いたのは第1船と第2船のみであった。

五島市三井楽 空海『「辞本涯」(日本さいはての地を去るの意)の碑』






8月中旬以降になると、大勢の人たちが関わって曼荼羅や密教法具の製作、経典の書写が行われた。恵果和尚からは阿闍梨付嘱物を授けられた。伝法の印信である。阿闍梨付嘱物とは、金剛智 - 不空金剛 - 恵果と伝えられてきた仏舎利、刻白檀仏菩薩金剛尊像(高野山に現存)など8点、恵果和尚から与えられた健陀穀糸袈裟(東寺に現存)や供養具など5点の計13点である。対して空海は伝法への感謝を込め、恵果和尚に袈裟と柄香炉を献上している。










Emerging from obscurity[edit]

Cui Ziyu's Beliefs (崔子玉座右銘)

In 810 Kūkai emerged as a public figure when he was appointed administrative head of Tōdai-ji, the central temple in Nara, and head of the Sōgō (僧綱, Office of Priestly Affairs).

Shortly after his enthronement Saga became seriously ill, and while he was recovering, Heizei fomented a rebellion, which had to be put down by force. Kūkai petitioned the Emperor to allow him to carry out certain esoteric rituals which were said to "enable a king to vanquish the seven calamities, to maintain the four seasons in harmony, to protect the nation and family, and to give comfort to himself and others". The petition was granted. Prior to this, the government relied on the monks from the traditional schools in Nara to perform rituals, such as chanting the Golden Light Sutra to bolster the government, but this event marked a new reliance on the esoteric tradition to fulfill this role.

With the public initiation ceremonies for Saichō and others at Takaosan in 812, Kūkai became the acknowledged master of esoteric Buddhism in Japan. He set about organizing his disciples into an order - making them responsible for administration, maintenance and construction at the temple, as well as for monastic discipline. In 813 Kūkai outlined his aims and practices in the document called The admonishments of Konin. It was also during this period at Takaosan that he completed many of the seminal works of the Shingon School:

  • Attaining Enlightenment in This Very Existence

  • The Meaning of Sound, Word, Reality

  • Meanings of the Word Hūm

All of these were written in 817. Records show that Kūkai was also busy writing poetry, conducting rituals, and writing epitaphs and memorials on request. His popularity at the court only increased, and spread.

Meanwhile, Kukai's new esoteric teachings and literature drew scrutiny from a noted scholar-monk of the time named Tokuitsu, who traded letters back and forth in 815 asking for clarification. The dialogue between them proved constructive and helped to give Kūkai more credibility, while the Nara Schools took greater interest in esoteric practice.[4]

Mount Kōya[edit]

In 816, Emperor Saga accepted Kūkai's request to establish a mountain retreat at Mount Kōya as a retreat from worldly affairs. The ground was officially consecrated in the middle of 819 with rituals lasting seven days. He could not stay, however, as he had received an imperial order to act as advisor to the secretary of state, and he therefore entrusted the project to a senior disciple. As many surviving letters to patrons attest, fund-raising for the project now began to take up much of Kūkai's time, and financial difficulties were a persistent concern; indeed, the project was not fully realised until after Kūkai's death in 835.

Kūkai's vision was that Mt. Kōya was to become a representation of the Mandala of the Two Realmsthat form the basis of Shingon Buddhism: the central plateau as the Womb Realm mandala, with the peaks surrounding the area as petals of a lotus; and located in the centre of this would be the Diamond Realm mandala in the form of a temple which he named Kongōbu-ji — the Diamond Peak Temple. At the center of the temple complex sits an enormous statue of Vairocana, who is the personification of Ultimate Reality.

















天長元年(824年)2月、勅により神泉苑で祈雨法を修した。3月には少僧都に任命され、僧綱入り(天長4年には大僧都)。6月に造東寺別当。9月には高雄山寺が定額寺となり、真言僧14名を置き、毎年年分度者一名が許可となった。 天長5年(828年)には『綜藝種智院式并序』を著すとともに、東寺の東にあった藤原三守の私邸を譲り受けて私立の教育施設「綜芸種智院」を開設。当時の教育は、貴族や郡司の子弟を対象にするなど、一部の人々にしか門戸を開いていなかったが、綜芸種智院は庶民にも教育の門戸を開いた画期的な学校であった。綜芸種智院の名に表されるように、儒教・仏教・道教などあらゆる思想・学芸を網羅する総合的教育機関でもある。『綜藝種智院式并序』において「物の興廃は必ず人に由る。人の昇沈は定んで道にあり」と、学校の存続が運営に携わる人の命運に左右される不安定なものであることを認めたうえで、「一人恩を降し、三公力をあわせ、諸氏の英貴諸宗の大徳、我と志を同じうせば、百世継ぐを成さん」と、天皇、大臣諸侯や仏教諸宗の支持・協力のもとに運営することで恒久的な存続を図る方針を示している。ただし、これは実現しなかったらしく、綜芸種智院は空海入滅後10年ほどで廃絶した。現在は種智院大学および高野山大学がその流れを受け継いでいる。










Public works[edit]

In 821 Kūkai took on a civil engineering task, that of restoring Manno Reservoir, which is still the largest irrigation reservoir in Japan.[5] His leadership enabled the previously floundering project to be completed smoothly, and is now the source of some of the many legendary stories which surround his figure. In 822 Kūkai performed an initiation ceremony for the ex-emperor Heizei. In the same year Saichō died.

Tō-ji Period[edit]

Letter to Saichō, stored in Tō-jiKobo Daishi in Daishoin Miyajima

When Emperor Kanmu had moved the capital in 784, he had not permitted the powerful Buddhists from the temples of Nara to follow him. He did commission two new temples: Tō-ji (Eastern Temple) and Sai-ji(Western Temple) which flanked the road at southern entrance to the city, protecting the capital from evil influences. However, after nearly thirty years the temples were still not completed. In 823 the soon-to-retire Emperor Saga asked Kūkai, experienced in public works projects, to take over Tō-ji and finish the building project. Saga gave Kūkai free rein, enabling him to make Tō-ji the first Esoteric Buddhist centre in Kyoto, and also giving him a base much closer to the court, and its power.

The new emperor, Emperor Junna (r. 823-833) was also well disposed towards Kūkai. In response to a request from the emperor, Kūkai, along with other Japanese Buddhist leaders, submitted a document which set out the beliefs, practices and important texts of his form of Buddhism. In his imperial decree granting approval of Kūkai's outline of esoteric Buddhism, Junna uses the term Shingon-shū (真言宗 Mantra Sect) for the first time. An imperial decree gave Kūkai exclusive use of Tō-ji for the Shingon School, which set a new precedent in an environment where previously temples had been open to all forms of Buddhism. It also allowed him to retain 50 monks at the temple and train them in Shingon. This was the final step in establishing Shingon as an independent Buddhist movement, with a solid institutional basis with state authorization. Shingon had become legitimate.

In 824 Kūkai was officially appointed to the temple construction project. In that year he founded Zenpuku-ji, the second oldest temple of the Edo(Tokyo) region. In 824 he was also appointed to the Office of Priestly Affairs. The Office consisted of four positions, with the Supreme Priest being an honorary position which was often vacant. The effective head of the Sōgō was the Daisōzu (大僧都 Senior Director). Kūkai's appointment was to the position of Shōsōzu (小僧都 Junior Director).[2] In addition there was a Risshi (律師 Vinaya Master) who was responsible for the monastic code of discipline. At Tō-ji, in addition to the main hall (kondō) and some minor buildings on the site, Kūkai added the lecture hall in 825 which was specifically designed along Shingon Buddhist principles, which included the making of 14 Buddha images. Also in 825, Kūkai was invited to become tutor to the crown prince. Then in 826 he initiated the construction of a large pagoda at Tō-ji which was not completed in his lifetime (the present pagoda was built in 1644 by the third Tokugawa Shogun, Tokugawa Iemitsu). In 827 Kūkai was promoted to be Daisōzu in which capacity he presided over state rituals, the emperor and the imperial family.

The year 828 saw Kūkai open his School of Arts and Sciences (Shugei shuchi-in). The school was a private institution open to all regardless of social rank. This was in contrast to the only other school in the capital which was only open to members of the aristocracy. The school taught Taoism and Confucianism, in addition to Buddhism, and provided free meals to the pupils. The latter was essential because the poor could not afford to live and attend the school without it. The school closed ten years after Kūkai's death, when it was sold in order to purchase some rice fields for supporting monastic affairs.







Final years[edit]

Monks bringing food to Kōbō Daishi on Mount Kōya, as they believe he is not dead but rather meditating. They feed him every day and change his clothes. No one except the highest monks are allowed to see him.

Kūkai completed his magnum opus, The Jūjūshinron (十住心論 Treatise on The Ten Stages of the Development of Mind) in 830. Because of its great length, it has yet to have been fully translated into any language. A simplified summary, Hizō Hōyaku (秘蔵宝鑰 The Precious Key to the Secret Treasury) followed soon after. The first signs of the illness that would eventually lead to Kūkai's death appeared in 831. He sought to retire, but the emperor would not accept his resignation and instead gave him sick leave. Toward the end of 832 Kūkai was back on Mt. Kōya and spent most of his remaining life there. In 834 he petitioned the court to establish a Shingon chapel in the palace for the purpose of conducting rituals that would ensure the health of the state. This request was granted and Shingon ritual became incorporated into the official court calendar of events. In 835, just two months before his death, Kūkai was finally granted permission to annually ordain three Shingon monks at Mt. Kōya — the number of new ordainees being still strictly controlled by the state. This meant that Kōya had gone from being a private institution to a state-sponsored one.

With the end approaching, he stopped taking food and water, and spent much of his time absorbed in meditation. At midnight on the 21st day of the third month (835) he died at the age of 62.[6] Emperor Ninmyō(r. 833-50) sent a message of condolence to Mount Kōya, expressing his regret that he could not attend the cremation due to the time lag in communication caused by Mount Kōya's isolation. However, Kūkai was not given the traditional cremation, but instead, in accordance with his will, was entombed on the eastern peak of Mount Kōya. "When, some time after, the tomb was opened, Kōbō-Daishi was found as if still sleeping, with complexion unchanged and hair grown a bit longer."[7]

Legend has it that Kūkai has not died but entered into an eternal samadhi and is still alive on Mount Kōya, awaiting the appearance of Maitreya, the future Buddha.[7][8]







  • まず、木食修行を行う。

  • 死後、腐敗しないよう肉体を整える。

  • 米や麦などの穀類の食を断ち、水や木の実などで命を繋ぐ。

  • 次に、土中入定を行う。

  • 土中に石室を設け、そこに入る。

  • 竹筒で空気穴を設け、完全に埋める。

  • 僧は、石室の中で断食をしながら鐘を鳴らし読経するが、やがて音が聞こえなくなり、長い歳月と共に姿を現すとされる。

 日本にもミイラは存在している。これらは入定ミイラ、即身仏とよばれている。入定とは、僧や行者が断食の修行ののちに魂が永久に生き続ける状態に入ることを言う。 もともと「入定」の意味は禅定に入り、宗教的な瞑想に入ることで、死とは関係ない。しかし、世にいう「入定」とは簡単にいえば岩窟などの隔絶された密室に入り、長く深い瞑想に入ったように入寂すること、つまり死ぬということである。ただし、「自然死」と「入定」の違いは、入定が、死が近づくのを知ると結跏趺坐して宗教的瞑想に入って死んでゆくのに対し、自然死は何もせずに死んでゆく。この差がきわめて大切で、「入定」の死は、信仰的には死と見ず、深遠な瞑想の姿と考えるのである。  日本では、人は死ねば自然に還るという死生観であった。では、なぜミイラ信仰が起こったのか。まず、そのことからみてみる。 日本で最初の入定者は、853年高野山の奥の院で入定した空海(弘法大師)とされている。この空海の入定伝説こそが後のミイラ信仰に関係している。空海は三月二十一日の寅の刻(午前四時)大日如来の印を結び、座禅正坐の姿勢で入定した。それまでの一〇日間と四時間、弟子達と共に弥勒菩薩の宝号を唱えていたが、目を閉じ、言語(声)を発しなくなって入定した。しかし、その姿は生きているようで、死後四十九日経ってもまったく変わらず、髭と髪が伸びていた。これを剃り衣服をととのえ、石壇をつくって、梵語文字の陀羅尼(呪文・真言のこと、梵語「ダーラニ」の写音)を入れて、上に宝塔を建立し、仏舎利を安置した。  この空海の入定伝説は、多くの文献や説話が残っている。これらをみる限り、空海が入定したという話は本当であるように思ってしまう。しかし、『続日本後記』によると、淳和上皇が空海を弔った勅書に、高野山は遠い場所にあるので大師(空海)の亡くなった報せが伝わるのが遅く、使者を急いで行かせたが、遅すぎて火葬の手助けができなかったと、述べている。このことから、空海の遺体は火葬されたということがわかる。 「空海入定説」が発生したのは、空海死後百年以上経ってからのことである。この伝説がその後の日本の即身仏に与えた影響は大きかった。空海の入定説が脚色され、最後には土中入定とも結びついてしまったことが、湯殿山系即身仏を生んだ一つの要因とも言われている。少なくとも初期の即身仏である淳海上人、本明海上人は、この入定説話を知っていたようだ。更に1630年から150年以上に亘る羽黒山との抗争が直接的な契機となって、天台宗に改宗した羽黒山との差別化を図るために即身仏を多く作ったというのが真相と考えられている。  では、日本の即身仏は、同じ目的・理由でミイラ仏となったのだろうか。実はそれぞれ違うのである。その種類をいくつか挙げてみると、まず即身成仏論がある。即身成仏とは、真言密教の根本思想であり、その内容は一言で言えば「大日如来との一体化により現身のまま仏陀になる」ということのようだ。これが真言密教という宗教の最終的な目的という訳である。この「即身成仏」の思想が「遺体を残したまま成仏する」というものではないのは勿論である。  しかし、17世紀から18世紀の亘って続いた湯殿山(真言宗)と羽黒山(天台宗に改宗)の闘争の過程で、これらのミイラが相次いで登場することになった。これは「真言宗の湯殿山」を証明するために、更に湯殿山で各種の厳しい修行を耐え抜いた修験者の最高の修行形態として、「即身成仏を実践してみせたもの」と考えられている。経緯はともかくとして、「即身仏」という言葉は本来これら「即身成仏を実践した」ミイラにのみふさわしい。  次に弥勒信仰のミイラである。弥勒信仰とは「弥勒菩薩が五十六億七千万年後にこの世に下生し、菩提樹の下で三度の説法を行う。この結果、釈迦の救済できなかった282億人が救済される」という思想に基づく信仰である。昔から南岳慧思大師のように「弥勒の下生まで生きつづけることが出来ないので、仙人になって待ちたい」などと願文を立てた人も多くいたが、「弥勒の下生まで体を残したい」という考えでミイラになったものが存在する。

 ただ、これらのミイラは空海入定説の影響も受けている。というのは、空海入定説の成立の過程で、本来なかった弥勒信仰との結びつきが発生したからと考えられている。空海は弥勒思想を持っていなかったと言われるが、「御遺告」という文献に空海が「自分は死後、弥勒の兜卒天に往生して、五十六億余年の後弥勒とともに下生する」と言ったと記されており、このあたりから空海と弥勒信仰が結びついたと考えられる(「御遺告」は後世の改竄の可能性が指摘されている文献である)。  ところで、今、実際にどれくらい即身仏が残っているのだろうか。多くの入定の話があるわりに意外と少ないのである。湯殿山系即身仏を中心に十数体しか残っていない。  即身仏になるには、どうすればいいのだろうか。もっと多く残っている湯殿山系のものをみると、入定するまでに、とても厳しい修行をしなければならない。まず、湯殿山付近の仙人沢というところに行って、一千日、二千日、三千日などの願を立てても木食行をしながら修行する。                              木食行とは、木の実ぐらいしか口にしないという徹底した食事制限によって、生前から肉体の脂肪分を落とし、生きているうちに修行によってミイラになりやすくすることである。木食行は、穀物を絶つ修行で、穀絶ち、断穀などと呼ばれており、宗教的な修行としてとても重視された。穀絶ちには、五穀絶ちと十穀絶ちがある。五穀は米・麦・大豆・小豆・胡麻、これに蕎麦・黍・稗・唐黍・粟を加えて十穀とするともいわれるが、この穀物の種類は一定していない。  即身仏を志す行者たちは、進んでわが身を荒行の中に投じた後、土中入定が行われた。生きながら木棺の中に入り、土の中の石室におろしてもらい、息つき竹を地上に出して土をかけて埋められる。この中で鉦をたたき、読経をしながら死んでいった。そして三年三ヵ月後に掘りだされてミイラとなり、衣を着せられ厨子に安置され、即身仏として祀られるのである。  では、その即身仏はどのような背景から生まれたのだろうか。一つ言えることは、いずれも社会不安が背後にある。貧苦に悩む小作人の農民の信者たちを身をもって苦しむ人びとを救済しようとして入定し、一方で信者たちは、生前加持祈祷でめざましい法力を発揮した入定者を仏として祀り、なんとか自分たちの苦難をとり除いてもらおうと「即身さま」を作り上げたと深作氏も述べている。  「土中入定のような地下の暗闇の中での孤独な死では、自分が極楽往生できるといった自己の救済だけでは、とても耐えられるものではない。なにか精神的な強い支えがなければ、とうてい死の恐怖を克服できるものではない。そういう民族的な心意が、入定者が修生救済を遺言して死んでいくという、土中入定伝の他者救済信仰を伴ったと考えられる」と内藤正敏(1999)が述べているように、日本のミイラは他者救済信仰によって生まれたものであるといえるであろう。

禅」は、梵 dhyānaの音写「禅那」の略。 思いを静め、心を明らかにして真正の理を悟るための修行法。