To Udāyin
Udāyin Sutta  (SN 46:30)

I have heard that on one occasion the Blessed One was staying among the Sumbhas. Now there is a Sumbhan town named Sedaka. Then Ven. Udāyin went to the Blessed One and, on arrival, bowed down to him and sat to one side. As he was sitting there, he said to the Blessed One, “It’s amazing, lord. It’s astounding, how much they have done for me—my love & respect for the Blessed One, my sense of shame & compunction. Before, when I was a householder, I wasn’t appreciative of the Dhamma or the Saṅgha, but contemplating my love & respect for the Blessed One, my sense of shame & compunction, I went forth from home life into homelessness. The Blessed One taught me the Dhamma: ‘Such is form, such the origination of form, such the disappearance of form. Such is feeling… Such is perception… Such are fabrications… Such is consciousness, such the origination of consciousness, such the disappearance of consciousness.’

“Then, lord, when I was staying in an empty dwelling, turning over (in my mind) the setting upright & toppling over of these five clinging-aggregates, I directly knew as it had come to be, ‘This is stress… This is the origination of stress… This is the cessation of stress… This is the way of practice leading to the cessation of stress.’

“I have broken through to the Dhamma, lord, and have gained the path that—when I have developed & cultivated it—will lead me to such a state that, dwelling by means of it, I will discern, ‘Birth is ended, the holy life fulfilled, the task done. There is nothing further for the sake of this world.’

“I have gained mindfulness as a factor for awakening that—when I have developed & cultivated it—will lead me to such a state that, dwelling by means of it, I will discern, ‘Birth is ended, the holy life fulfilled, the task done. There is nothing further for the sake of this world.’

“I have gained analysis of qualities as a factor for awakening… persistence as a factor for awakening… rapture as a factor for awakening… calm as a factor for awakening… concentration as a factor for awakening…

“I have gained equanimity as a factor for awakening that—when I have developed & cultivated it—will lead me to such as a state that, dwelling by means of it, I will discern, ‘Birth is ended, the holy life fulfilled, the task done. There is nothing further for the sake of this world.’

“This, lord, is the path I have gained that—when I have developed & cultivated it—will lead me to such a state that, dwelling by means of it, I will discern, ‘Birth is ended, the holy life fulfilled, the task done. There is nothing further for the sake of this world.’”

“Excellent, Udāyin, excellent. For this is the path that you have gained that—when you have developed & cultivated it—will lead you to such as a state that, dwelling by means of it, you will discern, ‘Birth is ended, the holy life fulfilled, the task done. There is nothing further for the sake of this world.’”

See also: AN 3:87–88