俱舍論頌疏論本 30.42

30.42

釋曰：已善說此淨因道者，標讚道也。涅槃名淨。此無我道能證涅槃，名淨因道。我執已破，無我理成，名為善說。

Explanation: [The line] "Already well-spoken is this path of pure causes" states praise of the path. Nirvāṇa is called 'pure'. This path of non-self can realize nirvāṇa, and is called the 'path of pure causes'. Attachment to self has been refuted, and the principle of non-self established; hence it is called 'well-spoken'.