俱舍論記 13.170

13.170

「論曰至猶如無病」者，釋第一句，明勝義善。勝義是涅槃，此顯涅槃安穩名善，如人無病無苦安穩。又《正理》三十六一解云「或真解脫是勝，是義得勝義名。勝謂最尊無與等者，義謂別有真實體性。此顯涅槃無等實有故名勝義，如是勝義安穩名善。如是涅槃是善常故，於一切法其體最尊，是故獨標為勝義善。

Regarding "The treatise says... like being free from illness": this explains the first line, clarifying ultimate good. The ultimate is nirvāṇa; this reveals that the security and peace of nirvāṇa is called good, like a person who is free of illness, without suffering, secure and at peace. Furthermore, Nyāyānusāra 36 provides an explanation: "Or true liberation is supreme (parama) and is an object (artha), hence it receives the name ultimate (paramārtha). 'Supreme' means the most exalted, with none equal to it; 'object/reality' means having a distinct, real intrinsic essence. This reveals that nirvāṇa is unequalled and real, hence called ultimate; such an ultimate, being secure and peaceful, is called good. Because such nirvāṇa is good and permanent, its essence is the most exalted among all dharmas; therefore it alone is designated as ultimate good."