俱舍論疏 17.94

17.94

論「身語七支至靜慮律儀」，明七善業。於此二處決定成就定不現行。准此論文，生無想天定不入定，以七善業定不現行故。

The passage of the śāstra from "The seven physical and vocal branches" up to "the saṃvara of dhyāna" explains the seven wholesome karmas. In these two places, they are definitely possessed and definitely not currently active. According to this śāstra text, those born in the heaven of non-conception definitely do not enter meditative absorption, because the seven wholesome karmas are definitely not currently active.