俱舍論頌疏論本 18.137

18.137

釋曰：等引者，定也，謂離沈掉名之為等，引生功德名之為引。此定地善極能熏心，令成德類，故獨名修。

Explanation: "Equally poised" (samāhita) refers to absorption; being free from torpor and restlessness is called "equal," and drawing forth virtues is called "poised." Wholesomeness of this ground of concentration can exceedingly perfume the mind, causing it to become of the nature of virtue; therefore, it alone is called cultivation.