摩訶止觀 9.65

9.65

三、淨背捨身作證者：初禪、二禪非遍身樂，四禪無樂何所為證？《成論》人四禪共淨背捨。今以兩禪共淨背捨。既言三禪有遍身樂，可以為證，即是其初，成就在四禪，能具足勝處。故知淨背捨位在三禪也。淨者，《釋論》云：「緣淨故淨。」八色已是淨法，而未被淨緣瑩練。淨色極在四禪，此色起時瑩於八色，更轉明淨，故言「緣淨故淨」。遍身受者，樂之極在三禪，故總此二禪為淨背捨也。淨有四義：不淨不淨者，欲界之身已是不淨，而今膖脹，故言「不淨不淨」；不淨淨者，除却皮肉，諦觀白骨，無腹筋血，如珂如貝，故言「不淨淨」；淨不淨者，是眉間所出八色光明，光明是淨，未被練治，故言「淨不淨」也；淨淨是第三背捨，更被淨緣練治也，故言「淨淨」。

Third, the realization of the liberation through the pure in one's own body: In the first and second dhyānas, bliss does not pervade the entire body; in the fourth dhyāna there is no bliss, so what could serve as the realization? Scholars of the *Satyasiddhiśāstra* assign the pure liberation solely to the fourth dhyāna. Here, we combine two dhyānas for the pure liberation. Since it is said that in the third dhyāna there is bliss pervading the entire body, this can serve as the realization—which is its initial stage; its culmination lies in the fourth dhyāna, enabling the complete fulfillment of the bases of mastery (abhibhvāyatana). Thus we know that the pure liberation is situated in the third dhyāna. As for 'pure,' the *Mahāprajñāpāramitopadeśa* says, 'It is pure because its objective support is pure.' The eight colors are already pure phenomena, yet they have not been refined and polished by pure conditions. Pure form reaches its culmination in the fourth dhyāna; when this form arises, it polishes the eight colors, making them even more bright and pure, hence the statement: 'It is pure because its objective support is pure.' As for experiencing it with the whole body, bliss reaches its peak in the third dhyāna; therefore, these two dhyānas are combined as the pure liberation. Purity has four meanings: 'Impure-impure' means the body of the desire realm is already impure, and now it swells and bloats, hence 'impure-impure.' 'Impure-pure' means shedding the skin and flesh to closely contemplate the white bones, free of viscera, sinews, and blood, like jade or conch shell, hence 'impure-pure.' 'Pure-impure' refers to the lights of the eight colors emerging between the eyebrows; light is pure, but it has not yet been refined and purified, hence 'pure-impure.' 'Pure-pure' is the third liberation, being further refined and purified by pure conditions, hence 'pure-pure.'