瑜伽師地論略纂 2.75

2.75

Regarding "the eighteen places of the form realm": there are three each in the lower three dhyānas, and eight in the fourth dhyāna; the non-conceptual heaven (Asaṃjñisattva) is included within Great Fruit (Bṛhatphala) and therefore is not stated separately, and with the addition of Maheśvara there are eighteen. In each of the four dhyānas there are three heavens, for which only perfumed cultivation is mentioned; hence this is perfuming only with outflows. Since it is said that birth in the five pure abodes (Śuddhāvāsa) is due to mixed cultivation of five grades, this clearly applies to the method of mixed cultivation with and without outflows. It does not differ from the old explanation: although the karma is created at the stage of an ordinary person, because the concentration with outflows is now augmented by the outflow-free, it further assists that past karma, bringing about superior rebirth in the abode of Maheśvara.