高僧傳 7.17

7.17

At that time, Yan Yanzhi wrote the "Lishi guan" (Contemplation on the Separation of Consciousness) and the "Lun jian" (Critical Treatise), and the Emperor ordered Yan to analyze their agreements and differences; they debated back and forth all day. The Emperor smiled and said: "You gentlemen today need feel no shame before Zhi [Daolin] and Xu [Xun]." Later, Yan wrote the "Wushengmie lun" (Treatise on Non-Arising and Non-Ceasing) and the Laozi lüezhu (Abridged Commentary on Laozi), and other works. He Chengtian of Donghai, renowned for his broad erudition, asked Yan what calendar the Buddhist countries used. Yan said: "In Tianzhu, at midday on the summer solstice, there is no shadow, which is called the Center of Heaven; in the Five Phases it corresponds to Earth virtue, its favored color is yellow, its favored number is five, eight inches make one foot, ten ounces equal twelve ounces of this land, and the month of the Chen branch is the start of the year." When examining equinoxes and solstices, calculating and verifying eclipses, and measuring the sun's shadow, his methods were extremely detailed, and the stellar degrees and chronology were all systematically organized. Chengtian had no objections to raise. Later, when people from the kingdom of Boli arrived, their accounts indeed matched Yan's words. The Emperor ordered Ren Yu to study them from him.