[391] Then a certain bhikkhu approached the Blessed One; having approached and paid homage to the Blessed One, he sat down to one side. Seated to one side, that bhikkhu said this to the Blessed One: "Here, venerable sir, while I was alone in seclusion, this reflection arose in my mind: 'Three feelings (vedanā) have been spoken of by the Blessed One: pleasant feeling, painful feeling, and neither-painful-nor-pleasant feeling. These three feelings have been spoken of by the Blessed One. But this too has been said by the Blessed One: "Whatever is felt is included in suffering (dukkha)." With reference to what was this said by the Blessed One: "Whatever is felt is included in suffering"?'"
"Good, good, bhikkhu! Three feelings, bhikkhu, have been spoken of by me: pleasant feeling, painful feeling, and neither-painful-nor-pleasant feeling. These three feelings have been spoken of by me. And this too, bhikkhu, has been said by me: 'Whatever is felt is included in suffering.' That, bhikkhu, was said by me with reference to the very impermanence of volitional formations: 'Whatever is felt is included in suffering.' And that, bhikkhu, was said by me with reference to volitional formations' very nature of being subject to destruction, subject to vanishing, subject to fading away, subject to cessation, and subject to change: 'Whatever is felt is included in suffering.'"
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.