俱舍論記 24.161

24.161

「由經說故至上界定無」者，答，由經說故。經言：有五補特伽羅，此欲界處通達四諦，彼上界處究竟漏盡，所謂中般乃至上流。此通達言唯目見道，是證涅槃初加行故。經既不言彼處通達，由此見道上界定無。

Regarding "Because a sūtra says ... upper realms definitely lack it": this is the answer, because a sūtra says so. A sūtra says: "There are five individuals who thoroughly penetrate the four noble truths in this place, the desire realm, and utterly end their outflows in that place, the upper realms—namely, those who attain nirvāṇa in the intermediate state up to the highest stream." This word "penetrate" refers only to the path of seeing, because it is the initial preparatory effort for realizing nirvāṇa. Since the sūtra does not say that they penetrate in that place, the upper realms definitely lack this path of seeing.