釋禪波羅蜜次第法門 5.121

5.121

復次，二禪喜樂等發，不從外來，一心澄淨大喜，美妙清淨，勝初禪故，論云：「內心清淨故，定生得喜樂，得入此二禪，喜勇心大悅。」云何名為內淨？遠而言之，對外塵故，說內淨；近而言之，對內垢故，說內淨。所以者何？如初禪中得觸樂時，身即明淨，兼令心淨。觸是身識相應，故名外淨。今待初禪外淨，故說二禪心識相應為內淨，亦令身淨，淨身故，名外淨。內淨是心淨，淨從心出，令身亦淨，故言內淨。今言待內垢，故說內淨者，初禪之中，心為覺觀所動，故名為內垢。今得二禪，內心無有覺觀之垢，故名為內淨。言定生得喜樂者，上於初禪說離生，今此說定生，義意云何？正言初禪離欲界，生色界定法故，二禪既無此義，但說定生。

Furthermore, the manifestation of prīti, sukha, and so forth in the second dhyāna does not come from outside; the single mind is clear, pure, and has great prīti, which is exquisite and pure, superior to the first dhyāna. Therefore the treatise says: 'Because the inner mind is pure, / Born of samādhi, one attains prīti and sukha; / Attaining entry into this second dhyāna, / With surging prīti the mind is exceedingly delighted.' What is called 'internal purity'? Remotely speaking, it is called internal purity in contrast to external sense-objects; proximately speaking, it is called internal purity in contrast to internal defilements. Why is this? Just as when one attains the pleasure of tactile sensation in the first dhyāna, the body becomes clear and pure, simultaneously causing the mind to become pure. Tactile sensation is associated with body-consciousness, and is therefore called external purity. Now, in contrast to the external purity of the first dhyāna, the association with mental consciousness in the second dhyāna is called internal purity, which also purifies the body; because it purifies the body, it is called external purity. Internal purity is mental purity; purity emerges from the mind and causes the body to be pure as well, hence it is called internal purity. Now, as for saying it is called internal purity in contrast to internal defilements: in the first dhyāna, the mind is agitated by vitarka and vicāra, and is therefore called internal defilement. Now, having attained the second dhyāna, the inner mind is free from the defilement of vitarka and vicāra, and is therefore called internal purity. As for 'born of samādhi, one attains prīti and sukha': previously, in the first dhyāna, it was called 'born of detachment', but here it is called 'born of samādhi'—what is the intended meaning? It refers precisely to the fact that the first dhyāna departs from the desire realm and generates the samādhi-factors of the form realm; since the second dhyāna lacks this meaning, it is merely called 'born of samādhi'.