俱舍論記 13.177

13.177

「勝義不善至猶如痼疾」者，答，明勝義不善。謂生死法苦諦為性，極不安穩，名勝義不善，如人痼疾恒苦不安。生死翻涅槃，涅槃是勝義善故，生死是勝義不善。問：不善翻於善，勝義不善通三性。亦可以善翻不善，勝義之善通三性。解云：勝義不善遍有漏故得通三性。勝義善法但擇滅，唯善，不通三性。

Regarding the passage from "The unwholesome in the ultimate sense..." up to "like a chronic illness": this answers, clarifying the unwholesome in the ultimate sense. The phenomena of cyclic existence have the noble truth of suffering as their nature and are extremely insecure; hence they are called "unwholesome in the ultimate sense," just as a person with a chronic illness is constantly suffering and insecure. Cyclic existence is the opposite of nirvāṇa; because nirvāṇa is good in the ultimate sense, cyclic existence is unwholesome in the ultimate sense. Question: The unwholesome is the opposite of the good, and the unwholesome in the ultimate sense applies across the three natures. Could one also say that the good is the opposite of the unwholesome, so that the good in the ultimate sense applies across the three natures? Explanation: The unwholesome in the ultimate sense pervades all sāsrava phenomena, and therefore applies across the three natures. Phenomena that are good in the ultimate sense comprise only analytical cessation (pratisaṃkhyā-nirodha), which is exclusively good and does not apply across the three natures.