釋迦方志 1.13

1.13

所言名者。咸謂西域以為中國。又亦名為中天竺國。此土名賢談邽之次。復指西宇而為中國。若非中者凡聖兩說不應名中。昔宋朝東海何承天者。博物著名群英之最。問沙門慧嚴曰。佛國用何曆術而號中乎。嚴云。天竺之國。夏至之日方中無影。所謂天地之中平也。此國中原景圭測之故有餘分。致曆有三代大小二。餘增損積算時輒差候明非中也。承天無以抗言。文帝聞之乃勅任豫受焉。

Regarding the name: all call the Western Regions the Middle Kingdom, and it is also called Central India. When the renowned worthies of this land conversed at Tuangui, they also referred to the Western Realm as the Middle Kingdom. If it were not the centre, both mundane and sacred accounts would not call it the centre. Formerly, under the Song dynasty, He Chengtian of Donghai was famous for his wide erudition and was foremost among the talented. He asked the śramaṇa Huiyan: 'What calendar system does the Buddha's country use to be called the centre?' Huiyan said: 'In the country of Tianzhu, on the summer solstice, there is no shadow at noon; this is what is called the level centre of heaven and earth. In the Central Plains of this country, when measuring with the sundial gnomon, there are fractional residues. Consequently, the calendars of the Three Dynasties had large and small [months] and intercalations, and by accumulating calculations there were constant deviations in the seasons, which clearly shows this is not the centre.' He Chengtian had no words to counter this. When Emperor Wen heard of it, he ordered Ren Yu to study it [under him].