成唯識論述記 7.266

7.266

述曰：此意說言：彼天本有初位，必有轉識起，天中本有之初位故，如餘天趣本有初位，法爾受生必初有六識。此非生有，謂在本有初位，然非即次生有後第二念時，本有之第一念心也，謂一期本有生三分分之，第一位名初位，不爾，卵生等本有初念，非必有意識故。《攝論》無性第三亦說：初生有心。勢與此同。

The Commentary states: The meaning here is to say: in the initial stage of the basic existence of that heaven, an evolving consciousness necessarily arises. Because it is the initial stage of basic existence in heaven, like the initial stage of basic existence in other heavenly destinies, by natural order, upon taking rebirth there must initially be the six consciousnesses. This is not intermediate existence; it refers to being in the initial stage of basic existence, yet it is not the very first thought-moment of basic existence at the second moment immediately following rebirth-existence. That is to say, dividing a single period of basic existence into three parts, the first part is termed the initial stage. Were it not so, the initial moment of basic existence in oviparous birth and the like would not necessarily possess mental consciousness. Asvabhāva's commentary on the third fascicle of the Mahāyānasaṃgraha also states that upon initial rebirth there is a mind. Its import is identical with this.