Mahāvagga

Suttapiṭaka · Khuddakanikāya · Paṭisambhidāmagga · Vol. 31 · Section 116

[116] Knowledge (ñāṇa) in the state of peace (santipada): "Arising is suffering (dukkha); non-arising is happiness." Knowledge in the state of peace: "Occurrence is suffering; non-occurrence is happiness." … Knowledge in the state of peace: "Despair is suffering; non-despair is happiness."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.