[189] The Blessed One said this: "Bhikkhus, here a bhikkhu, when thoroughly investigating, thoroughly investigates thus: 'This suffering (dukkha) of many kinds and various forms that arises in the world, namely aging and death — what now is the source of this suffering, what is its origin (samudaya), from what is it born, from what is it produced? When what exists do aging and death come to be? When what does not exist do aging and death not come to be?' Thoroughly investigating, he understands thus: 'This suffering of many kinds and various forms that arises in the world, namely aging and death — this suffering has birth (jāti) as its source, birth as its origin; it is born from birth, produced from birth. When birth exists, aging and death come to be; when birth does not exist, aging and death do not come to be.' He understands aging and death, he understands the origin of aging and death, he understands the cessation (nirodha) of aging and death, and he understands the way of practice (paṭipadā) that leads on in conformity with the cessation of aging and death; and he is one practicing thus, one who conducts himself in accordance with the Dhamma (anudhammacārī). This bhikkhu, bhikkhus, is called one practicing for the rightful destruction of suffering in its entirety, for the cessation of aging and death."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.