坐禪三昧經 2.21

2.21

或曰：「外事是樂，因緣不必是樂，或時樂因、或時苦因。若使心法與愛相應，爾時是樂；與恚相應，爾時是苦；與癡相應，不苦不樂。以此推之，可知有樂無樂。」

Someone may ask: "External objects are pleasure; causes and conditions are not necessarily pleasure, being sometimes causes of pleasure and sometimes causes of suffering. If mental dharmas are associated with craving, then there is pleasure; when associated with anger, then there is suffering; when associated with delusion, there is neither suffering nor pleasure. Deducing from this, one can know whether there is pleasure or no pleasure."