The Related Suttas Collection 48.45

5. Old Age

At the Eastern Monastery (1st)

So I have heard. At one time the Buddha was staying near Sāvatthī in the Eastern Monastery, the stilt longhouse of Migāra’s mother. There the Buddha addressed the bhikkhus: “Bhikkhus, how many faculties must a bhikkhu develop and cultivate so that they can declare enlightenment: ‘I understand: “Rebirth is ended, the spiritual journey has been completed, what had to be done has been done, there is no return to any state of existence”’?”

“Our teachings are rooted in the Buddha. …”

“A bhikkhu must develop and cultivate one faculty so that they can declare enlightenment. What one? The faculty of wisdom. When a noble disciple has wisdom, the faith, energy, mindfulness, and samādhi that follow along with that become stabilized. This is the one faculty that a bhikkhu must develop and cultivate so that they can declare enlightenment: ‘I understand: “Rebirth is ended, the spiritual journey has been completed, what had to be done has been done, there is no return to any state of existence”’.”