Dīrgha Āgama, Great Discourse on Causes, Sūtra Nine

Original text:云何二入处。无想入。非想非无想入是为。阿难。此二入处。或有沙门婆罗门言。此处安隐。为救为护。为舍为灯。为明为归。为不虚妄。为不烦恼。阿难。若比丘知二入处。知集知灭。知味知过。知出要。如实知见。彼比丘言。彼非我。我非彼。如实知见。是为二入。 

Explanation: What are the two bases of entry? The base of entry into the sphere of no perception and the base of entry into the sphere of neither perception nor non-perception are the two bases of entry. Ānanda, regarding these two bases of entry, some śramaṇas and brāhmaṇas say that they are a place of peace and security, a place of rescue and protection, a dwelling, a place of bright lamps, a place of light, a place of refuge, a place that is not false, and a place without afflictions. Ānanda, if bhikṣus know these two bases of entry, know their arising and cessation, know their flavor and faults, and know the essential way to escape from them, and contemplate and realize them as they truly are, those bhikṣus will say: those two bases of entry are not me, and I am not those two bases of entry. Contemplating and realizing this truth as it truly is—these are the two bases of entry. 

Original text:阿难。复有八解脱。云何八。色观色。初解脱。内无色想。观外色。二解脱。净解脱。三解脱。度色想。灭有对想。不念杂想。住空处。四解脱。度空处。住识处。五解脱。度识处。住不用处。六解脱。度不用处。住有想无想处。七解脱。灭尽定。八解脱。阿难。诸比丘于此八解脱。逆顺游行。入出自在。如是比丘得俱解脱。尔时。阿难闻佛所说。欢喜奉行。 

Explanation: Ānanda, there are also the eight liberations. What are the eight? The first liberation is that when the mind has perceptions of form and craving for form, one contemplates the impurity of form; when the impurity of form is realized, the mind attains liberation. The second liberation is that when the mind has no perceptions of form internally, one contemplates the impurity of external form; when the impurity of form is realized, the mind attains liberation. The third liberation is liberation attained when both body and mind are pure. The fourth liberation is that by transcending perceptions of form, extinguishing perceptions that are opposed to form, not attending to form and without other miscellaneous perceptions, one dwells in the meditative concentration of the sphere of infinite space and attains liberation. The fifth liberation is that by passing beyond the sphere of infinite space, one dwells in the meditative concentration of the sphere of infinite consciousness and attains liberation. The sixth liberation is that by passing beyond the sphere of infinite consciousness, one dwells in the meditative concentration of the sphere of nothingness and attains liberation. The seventh liberation is that by transcending the sphere of nothingness, one dwells in the meditative concentration of neither perception nor non-perception and attains liberation. The eighth liberation is that by dwelling in the cessation of perception and feeling (saṃjñā-veditā-nirodha), one attains liberation. Ānanda, whether the bhikṣus enter these eight liberations in sequential order or in reverse order, they are at ease in entering and emerging from meditative concentration. Such bhikṣus have fully realized all eight liberations and are called arhats of liberation in both respects (ubhayatobhāga-vimukta), fully endowed with liberating wisdom as well as the four dhyānas and eight meditative absorptions.