[1306] "And how, bhikkhus, is mindfulness of breathing (ānāpānasati) developed, how is it made much of, so that it is of great fruit and great benefit? Here, bhikkhus, a bhikkhu, gone to the forest, or gone to the root of a tree, or gone to an empty dwelling, sits down; having folded his legs crosswise, set his body erect, and established mindfulness in front of him, just mindful he breathes in, mindful he breathes out. Breathing in long, he knows clearly, 'I breathe in long'; breathing out long, he knows clearly, 'I breathe out long.' Breathing in short, he knows clearly, 'I breathe in short'; breathing out short, he knows clearly, 'I breathe out short.' He trains thus: 'Experiencing the whole body, I shall breathe in'; he trains thus: 'Experiencing the whole body, I shall breathe out.' He trains thus: 'Calming the bodily formation (kāyasaṅkhāra), I shall breathe in'; he trains thus: 'Calming the bodily formation, I shall breathe out.' He trains thus: 'Experiencing rapture (pīti), I shall breathe in'; he trains thus: 'Experiencing rapture, I shall breathe out.' He trains thus: 'Experiencing pleasure (sukha), I shall breathe in'; he trains thus: 'Experiencing pleasure, I shall breathe out.' He trains thus: 'Experiencing the mental formation (cittasaṅkhāra), I shall breathe in'; he trains thus: 'Experiencing the mental formation, I shall breathe out.' He trains thus: 'Calming the mental formation, I shall breathe in'; he trains thus: 'Calming the mental formation, I shall breathe out.' He trains thus: 'Experiencing the mind (citta), I shall breathe in'; he trains thus: 'Experiencing the mind, I shall breathe out.' He trains thus: 'Gladdening the mind, I shall breathe in'; he trains thus: 'Gladdening the mind, I shall breathe out.' He trains thus: 'Concentrating the mind, I shall breathe in'; he trains thus: 'Concentrating the mind, I shall breathe out.' He trains thus: 'Liberating the mind, I shall breathe in'; he trains thus: 'Liberating the mind, I shall breathe out.' He trains thus: 'Contemplating impermanence (anicca), I shall breathe in'; he trains thus: 'Contemplating impermanence, I shall breathe out.' He trains thus: 'Contemplating fading away (virāga), I shall breathe in'; he trains thus: 'Contemplating fading away, I shall breathe out.' He trains thus: 'Contemplating cessation, I shall breathe in'; he trains thus: 'Contemplating cessation, I shall breathe out.' He trains thus: 'Contemplating relinquishment (paṭinissagga), I shall breathe in'; he trains thus: 'Contemplating relinquishment, I shall breathe out.' It is when mindfulness of breathing is developed thus, bhikkhus, made much of thus, that it is of great fruit and great benefit."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.