“Well then, Ānanda, listen and apply your mind well, I will speak.” “Yes, sir,” Ānanda replied. The Buddha said this: “Ānanda, how is immersion due to mindfulness of breathing developed and cultivated so that it is very fruitful and beneficial? It’s when a mendicant—gone to a wilderness, or to the root of a tree, or to an empty hut—sits down cross-legged, sets their body straight, and brings mindfulness to the present. Just mindful, they breathe in. Mindful, they breathe out. … They practice like this: ‘I’ll breathe in observing letting go.’ They practice like this: ‘I’ll breathe out observing letting go.’ That’s how immersion due to mindfulness of breathing, when developed and cultivated, is very fruitful and beneficial.

There’s a time when a mendicant is breathing in heavily, and they know: ‘I’m breathing in heavily.’ Breathing out heavily they know: ‘I’m breathing out heavily.’ Breathing in lightly they know: ‘I’m breathing in lightly.’ Breathing out lightly they know: ‘I’m breathing out lightly.’ They practice like this: ‘I’ll breathe in experiencing the whole body.’ They practice like this: ‘I’ll breathe out experiencing the whole body.’ They practice like this: ‘I’ll breathe in stilling the physical process.’ They practice like this: ‘I’ll breathe out stilling the physical process.’ At such a time a mendicant is meditating by observing an aspect of the body—keen, aware, and mindful, rid of covetousness and displeasure for the world. Why is that? Because the breath is a certain aspect of the body, I say. Therefore, at such a time a mendicant is meditating by observing an aspect of the body—keen, aware, and mindful, rid of covetousness and displeasure for the world.