俱舍論記 18.51

18.51

「彼顯一逆至訶責彼罪」者，答。通彼經言：彼經顯一逆由父及羅漢二緣所成。言造二逆，或以恩田、德田二門訶責始欠持罪。問：前三俱轉中言，如屬他生，俱時瞋、殺、盜。彼亦依止一故，有三業道俱時而轉。殺父、羅漢依止亦一，何妨得二逆？解云：瞋、殺、盜業殊故，別結業道；斷命是其一，故不結二逆。

Regarding "That reveals that one anantarya [...] reproaching his offense": this is the answer. Reconciling that sūtra's words: that sūtra reveals that a single anantarya was constituted by two conditions—the father and the arhat. The statement "committed two anantaryas" was to reproach Śikhaṇḍin's offense through the two gates of the field of benefaction and the field of virtues. Question: In the previous discussion of three transforming together, it said that if belonging to another's life, there are simultaneous hatred, killing, and theft; there, because the basis is also one, three paths of karma proceed simultaneously. When killing a father who is an arhat the basis is also one; what prevents obtaining two anantaryas? Explanation: Because the karmas of hatred, killing, and theft are distinct, separate paths of karma are determined; severing life is a single [action], so two anantaryas are not determined.