釋氏稽古略 3.127

3.127

一行禪師　高僧傳曰。釋一行。俗姓張。鉅鹿人也（今順德路冀州之域）。本名遂。則太宗朝郯國公公謹之支孫也。丱歲不群博於記誦。讀書不再覽。遇禪師普寂於嵩山。乃悟世幻。遂禮之為師出家剃染。隷中嶽嵩陽寺。專勤精進。久之往荊州當陽山。依慧悟律師習毘尼。抑詳究於陰陽讖緯之書。尋訪算術。未至天台國清寺。得盡寺僧之所蘊。自此聲名籍甚。睿宗景雲二年三月。詔之赴闕。辭疾不行。玄宗開元三年八月。帝遣禮部郎中張洽齎詔詣當陽山。起之至京。帝謂曰。師有何能。對曰。略能記覽。帝命中官取官籍示之。師周覽方畢。覆其本記唱數幅。帝不覺降榻稽首曰。師實聖人也。嘆嗟久之。留光泰殿。詔對無恒。占於災福若指於掌。開元九年四月。朝廷以麟德曆不驗。詔師改撰新曆。師推大衍數立術以應之。曰開元大衍曆五十二卷。編入唐書曆律志。邢和璞者道術人也。謂尹愔曰。一行和尚真聖人也。漢洛下閎造太初曆云。八百歲後當差一日。則有聖人定之。今年觀畢矣。屬大衍曆出正其差謬。則洛下閎之言可信。非聖人孰能預於斯矣。師學陀羅尼祕印於金剛智三藏。開元十一年十月。師製水運渾天黃道儀成。古未之有也。帝悅親為製銘。詔安武成殿以示百官。

Chan Master Yixing. The Biographies of Eminent Monks states: 'Śramaṇa Yixing's secular surname was Zhang, and he was a native of Julu (now Shunde Route, in the territory of Jizhou). His original name was Sui, and he was a collateral grandson of Zhang Gongjin, the Duke of Tan during the reign of Taizong. In his youth, he was extraordinary and extensively learned in memorization; he never had to read a book a second time. Meeting Chan Master Pujin on Mount Song, he awakened to the illusory nature of the world. He thereupon bowed to him as his master, left home, and was tonsured. He was affiliated with Songyang Temple on the Central Peak. Dedicated and diligent, after a long time he went to Mount Dangyang in Jingzhou, relying on Vinaya Master Huiwu to study the Vinaya. He also investigated thoroughly the books of yin-yang and apocryphal prognostication, and sought after mathematics. Before he even reached Guoqing Temple on Mount Tiantai, he was able to fully absorb what the monks of the temple possessed. From this time onward, his reputation was celebrated far and wide. In the third month of the second year of Ruizong's Jingyun era [711], he was summoned by imperial decree to the court, but he declined on grounds of illness and did not go. In the eighth month of the third year of Xuanzong's Kaiyuan era [715], the Emperor dispatched Zhang Qia, Director of the Bureau of Rites, carrying an imperial edict to Mount Dangyang, to summon him to the capital. The Emperor said to him, 'What ability do you possess, Master?' He replied, 'I am merely able to memorize and read.' The Emperor ordered a palace official to fetch an official register and show it to him. As soon as the master finished perusing it, he covered the original and recited several leaves from memory. Unconsciously stepping down from his couch, the Emperor prostrated himself and said, 'The Master is truly a sage!' He sighed in admiration for a long time. He kept him in the Guangtai Hall, summoning him for discussions at all times; his prognostications of calamity and fortune were as clear as pointing to his own palm. In the fourth month of the ninth year of Kaiyuan [721], because the Linde calendar was inaccurate, the court decreed that the master revise and compile a new calendar. The master deduced the numbers of the Great Expansion (Dayan) and established methods to align with them, producing the Kaiyuan Dayan Calendar in fifty-two fascicles, which was incorporated into the Treatise on Calendars and Harmonics in the Book of Tang. Xing Hepu, a master of Daoist arts, said to Yin Yin: 'The Monk Yixing is truly a sage. When Luoxia Hong of the Han dynasty created the Taichu calendar, he said: "After eight hundred years, it should be off by one day, and then a sage will rectify it." That observation is fulfilled this year. With the emergence of the Dayan calendar correcting its errors, Luoxia Hong's words are indeed trustworthy; who but a sage could anticipate this beforehand?' The master studied the dhāraṇīs and secret mudrās under Tripiṭaka Master Vajrabodhi. In the tenth month of the eleventh year of Kaiyuan [723], the master completed the construction of a water-powered armillary sphere for the ecliptic, something never seen in antiquity. The Emperor was delighted and personally composed an inscription for it, ordering it to be installed in the Wucheng Hall to display to the civil and military officials.