摩訶止觀 7.51

7.51

勤觀念處，名「正勤」。見思本起，名「已生惡」；觀於即空，令已生不生，故勤精進。塵沙無明，名「未生惡」；觀即假、即中，令未生不生，故勤精進。竭力盡誠，行四三昧，遮此二惡。一切智名「已生善」；此善易生，故言「泥洹道易得」也。道種智、一切種智名「未生善」；此分別智難生。空智已生，勤加增長；中智未生，令得開發。三觀無間，祇為生此二智耳。是四正勤亦能悟道，故言「一心勤精進故得三菩提」，不須餘法。若不入者，當是不勤，心過散動；須入善寂，審觀心性，名為「上定」。於上定中修如意足：欲、精進、心、思惟。

Diligently contemplating the smṛtyupasthānas is termed 'right exertion'. Delusions of view and thought having originally arisen is termed 'evil already arisen'; contemplating identity-with-emptiness causes what has already arisen not to arise, hence one exerts oneself diligently. [Delusions like particles of] dust and sand and avidyā are termed 'evil not yet arisen'; contemplating identity-with-the-provisional and identity-with-the-middle causes what has not yet arisen not to arise, hence one exerts oneself diligently. Exhausting one's strength and with full sincerity, one practices the four kinds of samādhi to obstruct these two kinds of evil. All-knowledge (sarvajñatā) is termed 'good already arisen'; this good easily arises, hence it is said, 'The path to nirvāṇa is easy to attain.' The knowledge of the aspects of the path (mārgākārajñatā) and sarvākārajñatā are termed 'good not yet arisen'; this discriminative knowledge is difficult to produce. The knowledge of emptiness having already arisen, one diligently augments it; the middle knowledge not having yet arisen, one causes it to be opened and developed. The three contemplations without interruption are solely for generating these two knowledges. These four right exertions can also awaken to the path; hence it is said, 'Because of single-minded diligent exertion, one attains the three bodhis,' with no need for other dharmas. If one does not enter, it must be because one is not diligent and the mind is excessively scattered and agitated; one must enter the excellent quiescence and closely scrutinize the nature of the mind, which is termed 'superior concentration'. Within this superior concentration, one cultivates the bases of spiritual power (ṛddhipāda): desire, exertion, mind, and scrutiny.