[406] How does one train thus: "Calming the bodily formation (kāyasaṅkhāra), I shall breathe out"; how does one train thus: "Calming the bodily formation, I shall breathe in"?
What is the bodily formation? Long out-breaths are bodily; these dhammas, being bound up with the body, are bodily formations. Calming, causing to cease, stilling those bodily formations, one trains. Long in-breaths are bodily; these dhammas, being bound up with the body, are bodily formations. Calming, causing to cease, stilling those bodily formations, one trains. Short out-breaths, short in-breaths, out-breaths experiencing the whole body are bodily; these dhammas, being bound up with the body, are bodily formations. Calming, causing to cease, stilling those bodily formations, one trains.
When there are such bodily formations whereby there is bending forward, bending back, bending sideways, and bending down of the body, wavering, trembling, moving, and shaking, one trains thus: "Calming the bodily formation, I shall breathe out"; one trains thus: "Calming the bodily formation, I shall breathe in." When there are such bodily formations whereby there is no bending forward, no bending back, no bending sideways, and no bending down of the body, no wavering, no trembling, no moving, and no shaking, one trains thus: "Calming the peaceful and subtle bodily formation, I shall breathe out"; one trains thus: "Calming the peaceful and subtle bodily formation, I shall breathe in."
So then, [if] one trains thus: "Calming the bodily formation, I shall breathe out," and trains thus: "Calming the bodily formation, I shall breathe in" — that being so, there is no development of the apprehension of the wind, there is no development of the out-breaths and in-breaths, there is no development of mindfulness of breathing (ānāpānasati), there is no development of concentration (samādhi) by mindfulness of breathing, and the wise neither enter into nor emerge from that attainment (samāpatti). So then, [if] one trains thus: "Calming the bodily formation, I shall breathe out," and trains thus: "Calming the bodily formation, I shall breathe in" — that being so, there is development of the apprehension of the wind, there is development of the out-breaths and in-breaths, there is development of mindfulness of breathing, there is development of concentration by mindfulness of breathing, and the wise both enter into and emerge from that attainment.
Like what? Just as when a bronze gong is struck, at first gross sounds occur, and because the sign (nimitta) of the gross sounds has been well grasped, well attended to, well borne in mind, then even when the gross sounds have ceased, afterwards subtle sounds occur; and because the sign of the subtle sounds has been well grasped, well attended to, well borne in mind, then even when the subtle sounds have ceased, afterwards the mind (citta) still occurs, because it has the subtle sign as its object — even so, at first gross out-breaths and in-breaths occur, and because the sign of the gross out-breaths and in-breaths has been well grasped, well attended to, well borne in mind, then even when the gross out-breaths and in-breaths have ceased, afterwards subtle out-breaths and in-breaths occur; and because the sign of the subtle out-breaths and in-breaths has been well grasped, well attended to, well borne in mind, then even when the subtle out-breaths and in-breaths have ceased, afterwards the mind does not fall into distraction, because it has the sign of the subtle out-breaths and in-breaths as its object.
That being so, there is development of the apprehension of the wind, there is development of the out-breaths and in-breaths, there is development of mindfulness of breathing, there is development of concentration by mindfulness of breathing, and the wise both enter into and emerge from that attainment.
Calming the bodily formation: the body of out-breaths and in-breaths is the establishment (upaṭṭhāna); mindfulness (sati) is the knowledge (ñāṇa) of contemplation. The body is the establishment, but it is not the mindfulness; mindfulness is both the establishment and the mindfulness. By means of that mindfulness and that knowledge one contemplates that body. Therefore it is called "the development of the establishment of mindfulness (satipaṭṭhāna) consisting in contemplating the body in the body."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.