成唯識論述記 7.270

7.270

述曰：彼天本有初，若無轉識，如何名入？要先有後無，乃名入故，非先未有心，可言入無心。先已入訖，何假言入。又非中有末可起報心，報心滅時，名入無心，諸論皆說：彼中有必起愛潤生心故。

The Commentary states: If there were no evolving consciousness at the beginning of the basic existence of that heaven, how could it be termed "entering"? One must first have [mind] and subsequently lack it to be called "entering"; one cannot say that having previously lacked a mind is "entering mindlessness." If one had already entered previously, why would one need to say "entering"? Furthermore, it is not that the end of intermediate existence can give rise to a retributive mind such that when that retributive mind ceases it is called "entering mindlessness," because all treatises state that the intermediate existence there necessarily gives rise to a craving mind that moistens rebirth.