[489] Bhikkhus, ardent effort (ātappa) should be made on three grounds. On which three? Ardent effort should be made for the non-arising of evil, unwholesome states that have not yet arisen; ardent effort should be made for the arising of wholesome states that have not yet arisen; ardent effort should be made for the endurance of arisen bodily feelings (vedanā) that are painful, racking, sharp, piercing, disagreeable, displeasing, and life-threatening. When, bhikkhus, a bhikkhu makes ardent effort for the non-arising of evil, unwholesome states that have not yet arisen, makes ardent effort for the arising of wholesome states that have not yet arisen, and makes ardent effort for the endurance of arisen bodily feelings that are painful, racking, sharp, piercing, disagreeable, displeasing, and life-threatening — this bhikkhu, bhikkhus, is called ardent (ātāpī), prudent, and possessed of mindfulness (sati) for rightly making an end of suffering (dukkha).
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.