AN6.20 — Dutiyamaraṇassatisutta

At one time, the Blessed One was dwelling 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.

How is mindfulness of death developed and cultivated to be of great fruit and benefit, leading to the deathless, having the deathless as its consummation?

Here a disciple reflects at the end of the day, as night falls:

There are many causes for my death: a snake might bite me, a scorpion might sting me, a centipede might bite me; that would be an obstacle for me. I might stumble and fall, the food I have eaten might cause me trouble, my bile or phlegm might be disturbed, or the bodily humors might be disturbed;that would be an obstacle for me.

Therefore a disciple should reflect:

Are there any evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die tonight?

If, upon reflection, a disciple knows:

There are evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die tonight, then that disciple should arouse extraordinary desire, effort, enthusiasm, resolution, mindfulness, and clear knowing for the abandoning of those very evil, unwholesome states.

Just as if one's clothes or head were on fire, one would exert extraordinary desire, effort, enthusiasm, resolution, mindfulness, and clear knowing to extinguish the fire on one's clothes or head; similarly that disciple should exert effort for the abandoning of those very evil, unwholesome states.

If, however, upon reflection, a disciple knows:

There are no evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die tonight, then that disciple should dwell with joy and happiness, training day and night in wholesome states.

Here a disciple reflects at the dawn of day:

Therefore a disciple should reflect:

Are there any evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die today?

If, upon reflection, a disciple knows:

There are evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die today, then that disciple should arouse extraordinary desire, effort, enthusiasm, resolution, mindfulness, and clear knowing for the abandoning of those very evil, unwholesome states.

If, however, upon reflection, a disciple knows:

There are no evil, unwholesome states not abandoned in me, which would be an obstacle if I were to die today, then that disciple should dwell with joy and happiness, training day and night in wholesome states.

Thus developed mindfulness of death is of great fruit and benefit, leading to the deathless, having the deathless as its consummation.