大般涅槃經義記 5.120

5.120

四約時分別，於中約對三緣辯時：若對違緣，相應時苦，離時生樂，久離則捨；若對順緣，初受生樂，中受時捨，久受則苦，或有順緣相應時樂，離時生苦，久離則捨；若對中緣初受時捨，久受生苦，離時生樂，或有中緣初受時捨，久受樂著則生樂受，離時生苦。三受如此，更有多義，廣如別章五陰中說。下辯三苦亦如別章釋。

Fourth, distinguishing in terms of time, wherein time is distinguished in relation to the three conditions: In relation to contrary conditions, there is suffering when associated with them, pleasure arises when separated from them, and equanimity when separated for a long time. In relation to accordant conditions, pleasure arises when first received, equanimity when experienced moderately, and suffering when received for a long time; or there are accordant conditions where there is pleasure when associated with them, suffering arises when separated from them, and equanimity when separated for a long time. In relation to neutral conditions, there is equanimity when first received, suffering arises when received for a long time, and pleasure arises when separated; or there are neutral conditions where there is equanimity when first received, and if one takes pleasure in and attaches to them for a long time, the feeling of pleasure arises, while suffering arises when separated. The three feelings are like this, and there are many further meanings, explained extensively in the separate chapter on the five aggregates. Below, the explanation of the three sufferings is also as explained in that separate chapter.