釋氏稽古略 3.127

3.127

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.