大般涅槃經義記 5.118

5.118

二對因分別，一切惡果斯名為苦，一切善果說為樂捨，是義云何？若依《雜心》，三禪已下一切善果斯名為樂，四禪已上一切善果斯名為捨。若依《成實》，善分為二：一欲界散善、二上界定善。散善之中，增上業果說為樂受，下品之樂說為捨受，以此微樂難覺知故。問曰：苦中亦有微下不善業果，何不名捨，偏說下樂為捨受乎？釋言：苦果違害之法，性與情返，微有即覺，故入苦中，不得名捨。樂果順情，非切心法，微者難覺，故分為捨。又復一切苦、樂二受皆用微細行苦為體，於行苦上宣說苦受，苦受必重，為心所覺，故不名捨。於行苦上宣說樂受，樂受必微，於中上者為心覺適，當相名樂，輕微之者非心能覺，轉名說捨。定善之中，下善業果說之為樂；四禪已上，勝善所得說之為捨，以彼寂靜難覺知故。

Second, distinguishing in terms of cause: all evil fruits are called suffering; all wholesome fruits are called pleasure and equanimity. What does this mean? If based on the *Saṃyuktābhidharma-hṛdaya-śāstra*, all wholesome fruits from the third dhyāna down are called pleasure, and all wholesome fruits from the fourth dhyāna up are called equanimity. If based on the *Tattvasiddhi-śāstra*, wholesome [actions] are divided into two: first, the scattered wholesome of the desire realm; second, the meditative wholesome of the higher realms. Within the scattered wholesome, the fruits of predominant karma are called the feeling of pleasure, and the lowest grade of pleasure is called the feeling of equanimity, because this subtle pleasure is difficult to perceive. Question: In suffering, there are also fruits of subtle, low unwholesome karma; why are they not called equanimity, while low pleasure is specifically called the feeling of equanimity? Answer: The fruits of suffering are dharmas of injury and harm; their nature runs contrary to sensory inclinations, so even a slight amount is immediately perceived, and thus it is subsumed under suffering and cannot be called equanimity. The fruits of pleasure accord with sensory inclinations and are not an acute mental dharma, so subtle ones are difficult to perceive, and are thus divided as equanimity. Furthermore, both feelings of suffering and pleasure take the subtle suffering of conditioning as their essence; when the feeling of suffering is proclaimed on top of the suffering of conditioning, the feeling of suffering is inevitably heavy and perceived by the mind, so it is not called equanimity. When the feeling of pleasure is proclaimed on top of the suffering of conditioning, the feeling of pleasure is inevitably subtle; the middle and upper levels among it are perceived as pleasant by the mind and are called pleasure according to their intrinsic mark, whereas those that are light and subtle cannot be perceived by the mind and are alternatively designated as equanimity. Within the meditative wholesome, the fruits of lower wholesome karma are called pleasure; from the fourth dhyāna upward, what is attained through superior wholesome karma is called equanimity, because its tranquility is difficult to perceive.