Dukkhatāsutta
“Tisso imā, bhikkhave, dukkhatā. Katamā tisso? Dukkhadukkhatā, saṅkhāradukkhatā, vipariṇāmadukkhatā— imā kho, bhikkhave, tisso dukkhatā. Imāsaṁ kho, bhikkhave, tissannaṁ dukkhatānaṁ abhiññāya pariññāya parikkhayāya pahānāya …pe… ayaṁ ariyo aṭṭhaṅgiko maggo bhāvetabbo”ti.
Forms of Suffering
“Mendicants, there are these three forms of suffering. What three? The suffering inherent in painful feeling; the suffering inherent in conditions; and the suffering inherent in perishing. These are the three forms of suffering. The noble eightfold path should be developed for the direct knowledge, complete understanding, finishing, and giving up of these three forms of suffering.”