AN6.19 — Paṭhamamaraṇassatisutta
At one time, the Blessed One was staying at Nātika in the Brick Hall. There, the Blessed One addressed the disciples:
Mindfulness of death, when developed and cultivated, is of great fruit and benefit, leading to the deathless, having the deathless as its consummation. Should you not cultivate mindfulness of death?
When this was said, a certain disciple said to the Blessed One: I, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple?
Here, venerable sir, it occurs to me: Oh, may I live for the night and day, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Another disciple said to the Blessed One: I too, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple? Here, venerable sir, it occurs to me: Oh, may I live for the day, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Another disciple said to the Blessed One: I too, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple? Here, venerable sir, it occurs to me: Oh, may I live for the time it takes to eat a meal, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Another disciple said to the Blessed One: I too, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple? Here, venerable sir, it occurs to me: Oh, may I live for the time it takes to eat four or five mouthfuls, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Another disciple said to the Blessed One: I too, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple? Here, venerable sir, it occurs to me: Oh, may I live for the time it takes to eat one mouthful, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Another disciple said to the Blessed One: I too, venerable sir, cultivate mindfulness of death. But how do you cultivate mindfulness of death, disciple? Here, venerable sir, it occurs to me: Oh, may I live for the time it takes to breathe in or out, keep the Blessed One's teaching in mind, much would be done by me. Thus, venerable sir, I cultivate mindfulness of death.
Having said this, the Blessed One said to the disciples: Disciples, whether a disciple cultivates mindfulness of death thinking: Oh, may I live for the night and day, or for the day, or for the time it takes to eat a meal, or for the time it takes to eat four or five mouthfuls, these disciples are said to live negligently, to cultivate mindfulness of death slowly for the destruction of the taints.
But whether a disciple cultivates mindfulness of death thinking: Oh, may I live for the time it takes to eat one mouthful, or for the time it takes to breathe in or out, these disciples are said to live diligently, to cultivate mindfulness of death sharply for the destruction of the taints. Therefore train yourselves thus.
Let us live heedfully, develop acute mindfulness of death for the destruction of the taints. Thus should you train yourselves.