俱舍論疏 24.142

24.142

「論曰至治自地故」，釋有頂染唯無漏斷。夫有漏道斷惑者，皆是次上地斷下地惑，自地不能治自地故。有頂無上地故，唯無漏斷。

On the statement: "The Śāstra says: up to because it remedies its own ground": This explains that the defilements of the summit of existence (bhavāgra) are severed exclusively by the anāsrava [path]. Whenever an āsrava path severs defilement, it is always the immediately higher ground severing the defilement of a lower ground, because a ground cannot remedy its own ground. Since the summit of existence has no higher ground, it is severed exclusively by the anāsrava [path].