Nagarasutta
Sāvatthiyaṁ viharati. “Pubbe me, bhikkhave, sambodhā anabhisambuddhassa bodhisattasseva sato etadahosi: ‘kicchā vatāyaṁ loko āpanno jāyati ca jīyati ca mīyati ca cavati ca upapajjati ca. Atha ca panimassa dukkhassa nissaraṇaṁ nappajānāti jarāmaraṇassa. Kudāssu nāma imassa dukkhassa nissaraṇaṁ paññāyissati jarāmaraṇassā’ti? Tassa mayhaṁ, bhikkhave, etadahosi: ‘kimhi nu kho sati jarāmaraṇaṁ hoti, kiṁpaccayā jarāmaraṇan’ti? Tassa mayhaṁ, bhikkhave, yoniso manasikārā ahu paññāya abhisamayo: ‘jātiyā kho sati jarāmaraṇaṁ hoti, jātipaccayā jarāmaraṇan’ti.
The City
At Sāvatthī. “Mendicants, before my awakening—when I was still unawakened but intent on awakening—I thought: ‘Alas, this world has fallen into trouble. It’s born, grows old, dies, passes away, and is reborn, yet it doesn’t understand how to escape from this suffering, from old age and death. Oh, when will an escape be found from this suffering, from old age and death?’ Then it occurred to me: ‘When what exists is there old age and death? What is a requirement for old age and death?’ Then, through rational application of mind, I penetrated with wisdom: ‘When rebirth exists there’s old age and death. Rebirth is a requirement for old age and death.’