翻譯名義集 3.120

3.120

【殑（巨升）伽】此云天堂來，見從高處來故。又云河神之名，以為河名。《西域記》：「舊曰恒河，又曰恒沙，訛也。」章安云：「諸經多以恒河沙為量者，有四義故：一、人多識之，二、入者得福，三、八河中大，四、是佛生處。此即四悉檀也。」

[Gaṅgā] Translated here as Coming from Heaven, because it is seen descending from a high place. Also said to be the name of the river goddess, taken as the name of the river. The Record of the Western Regions says: 'Formerly called Mount Heng or Heng sands, which are errors.' Zhang'an says: 'The sūtras often take the sands of the Gaṅgā River as a measure for four reasons: first, most people recognize it; second, those who enter it gain merit; third, it is the greatest among the eight rivers; fourth, it is the birthplace of the Buddha. These correspond to the four siddhāntas.'