At one time the Buddha was staying in a forest near Icchānaṅgala. There he addressed the mendicants, “Mendicants, I wish to go on retreat for three months. No-one should approach me, except the one who brings my almsfood.”
“Yes, sir,” replied those mendicants. And no-one approached him, except the one who brought the almsfood.
Then after three months had passed, the Buddha came out of retreat and addressed the mendicants:
“Mendicants, if wanderers who follow another religion were to ask you: ‘Reverends, what was the ascetic Gotama’s usual meditation during the rainy season residence?’ You should answer them like this. ‘Reverends, the ascetic Gotama’s usual meditation during the rainy season residence was immersion due to mindfulness of breathing.’
In this regard: mindful, I breathe in. Mindful, I breathe out.
Breathing in heavily I know: ‘I’m breathing in heavily.’ Breathing out heavily I know: ‘I’m breathing out heavily.’ Breathing in lightly I know: ‘I’m breathing in lightly.’ Breathing out lightly I know: ‘I’m breathing out lightly.’ I know: ‘I’ll breathe in experiencing the whole body.’ …
I know: ‘I’ll breathe in observing letting go.’ I know: ‘I’ll breathe out observing letting go.’
For if anything should be rightly called ‘a noble meditation’, or else ‘a divine meditation’, or else ‘a realized one’s meditation’, it’s immersion due to mindfulness of breathing.
For those mendicants who are trainees—who haven’t achieved their heart’s desire, but live aspiring to the supreme sanctuary from the yoke—the development and cultivation of immersion due to mindfulness of breathing leads to the ending of defilements.
For those mendicants who are perfected—who have ended the defilements, completed the spiritual journey, done what had to be done, laid down the burden, achieved their heart’s goal, utterly ended the fetter of continued existence, and are rightly freed through enlightenment—the development and cultivation of immersion due to mindfulness of breathing leads to blissful meditation in this life, and to mindfulness and awareness.
For if anything should be rightly called ‘a noble meditation’, or else ‘a divine meditation’, or else ‘a realized one’s meditation’, it’s immersion due to mindfulness of breathing.”