俱舍論疏 23.173

23.173

論「諸無漏道至說名預流」，釋預流名。諸無漏道趣向涅槃故名為流，即是聖道名之為流。最初至得名之為預，舊名入流，預是入之差別名也。彼七返人預聖道流，故名預流。

On the passage of the treatise from "All undefiled paths" to "are spoken of as stream-enterers": This explains the name 'stream-enterer' (*srotāpanna*). All undefiled paths tend toward nirvāṇa, and therefore are called a 'stream'; that is, the noble path is called a stream. Initial attainment is called 'entering' (*yu*); the older translation was 'entering the stream' (*ru liu*), and *yu* is an alternative name for 'entering'. Those people who return seven times enter the stream of the noble path, and therefore are called 'stream-enterers'.