佛祖統紀 36.58

36.58

十六年。罽賓沙門眾至江左（凡水自西而東。即以東為面。西為背。北為左手。南為右手。則江南當稱江右可也。自古誤稱江左者。不知背面左右之義也。今稱浙西為浙右者。同坐此誤。此說得之儒宗先生云）譯三法度經等三部。

In the sixteenth year, a group of śramaṇas from Kaśmīra arrived in the region east of the Yangtze (Whenever a river flows from west to east, it faces east, takes west as its back, north as its left, and south as its right; therefore the south of the Yangtze should properly be called 'west of the Yangtze'. Since ancient times, it has been erroneously called 'east of the Yangtze' because people did not understand the meaning of front, back, left, and right. Calling Western Zhejiang 'Right Zhejiang' today suffers from the same error. This explanation was obtained from Master Ruzong). They translated three texts, including the San fadu jing (Tridharmaka-śāstra).