俱舍論記 15.121

15.121

「無漏律儀至必不現起」者，釋後兩句。無漏律儀不但在欲、色界，亦在無色。謂若生在欲界天中，及生色界中，除中定梵王及無想天，以彼二處唯異生故。餘十六處，皆容得有無漏律儀。生無色中唯得成就下六地中無漏律儀，以無色故必不現行。

Regarding 'Anāsrava restraint ... to ... definitely does not become manifest': this explains the last two lines. Anāsrava restraint is not only in the desire and form realms, but also in the formless realm. That is, if one is born among the devas of the desire realm, or born in the form realm, except for the Great Brahmā of the intermediate dhyāna and the asaṃjñi-sattvā devas—because those two places are occupied solely by ordinary beings (pṛthagjana)—in the remaining sixteen places, in all cases one can possess anāsrava restraint. Born in the formless realm, one only achieves the anāsrava restraint belonging to the lower six stages; because it is formless, it definitely does not become manifest.