俱舍論疏 23.68

23.68

論「此四善根至遍知斷故」，此即第四明依地也。此四善根，修慧為體，是見道眷屬。欲界無修故，無色界無見道故，所以不通欲界、無色。又無色心不緣欲故。「欲界先應遍知斷」者，更釋無色無見道也。以欲先應遍知斷故，見道必先緣欲界。無色不緣欲，故無見道。所以欲界先遍知斷，《正理論》云「於三界中彼最麁故。」

The treatise says: "These four wholesome roots ... because they are abandoned through full knowledge." This is the fourth [section], clarifying their supporting stages. These four wholesome roots take the wisdom derived from cultivation as their essence and are retinue to the path of seeing. Because the desire realm lacks cultivation, and the formless realm lacks the path of seeing, they do not extend to the desire or formless realms. Furthermore, a mind of the formless realm does not take the desire realm as its condition. As for "the desire realm should first be abandoned through full knowledge," this further explains why the formless realm lacks the path of seeing. Because the desire realm should first be abandoned through full knowledge, the path of seeing must first take the desire realm as its condition. The formless realm does not take the desire realm as its condition, and therefore lacks the path of seeing. As to why the desire realm is first abandoned through full knowledge, the Nyāyānusāra states: "Because among the three realms it is the coarsest."