金剛經纂要刊定記 4.48

4.48

又云卵濕等者，舉難處難也。卵濕則畜生難，無想有頂即長壽天難，雖舉二處，意兼八難。八難，謂：三塗、北州、長壽天、佛前佛後、世智辯聰、無根等難。意云：難處即不可度，云何皆入？

It also says 'egg-born, moisture-born, etc.': this raises an objection based on the states of adversity. Egg-born and moisture-born are the adversity of animals; non-perception and the Peak of Existence are the adversity of the long-lived devas. Although two places are cited, the intention includes all eight adversities. The eight adversities are: the three wretched destinies, the Northern Continent, the long-lived devas, being born before or after a Buddha, worldly knowledge and debate, and being deficient in faculties. The meaning is: those in states of adversity cannot be liberated; how could they all enter [nirvāṇa]?