Mahasatipatthana Sutta
i. Anapana Pabba (Section on In and Out Breathing)

And how, bhikkhus, does a bhikkhu dwell perceiving again and again the body as just the body? Here (in this teaching), bhikkhus, a bhikkhu having gone to the forest, or to the foot of a tree, or to an empty, solitary place;note21 sits down cross-legged,note22 keeping his body erect, and directs his mindfulness (towards the object of mindfulness).note23Then only with keen mindfulness he breathes in and only with keen mindfulness he breathes out. Breathing in a long breath, he knows, “I breathe in a long breath”; breathing out a long breath, he knows, “I breathe out a long breath”; breathing in a short breath, he knows, “I breathe in a short breath”; breathing out a short breath, he knows, “I breathe out a short breath”, “Aware of the whole breath body, I shall breathe in”,note24 thus he trains himself; “Aware of the whole breath body, I shall breathe out”, thus he trains himself. “Calming the process of breathing, I shall breathe in”,note25 thus he trains himself; “Calming the process of breathing, I shall breathe out”, thus he trains himself.note26

Just as, bhikkhus, a skilful turner or a turner’s apprentice pulling a long pull (on the string turning the lathe), knows, “I am pulling a long pull”; pulling a short pull, knows, “I am pulling a short pull”, just so, bhikkhus, a bhikkhu breathing in a long breath, knows, “I breathe in a long breath”; breathing out a long breath, knows, “I breathe out a long breath”; breathing in a short breath, knows, “I breathe in a short breath”; breathing out a short breath, knows, “I breathe out a short breath”. “Aware of the whole breath body, I shall breathe in,” thus he trains himself; “Aware of the whole breath body, I shall breathe out”, thus he trains himself. “Calming the process of breathing, I shall breathe in”, thus he trains himself; “Calming the process of breathing, I shall breathe out”, thus he trains himself.

Thus he dwells perceiving again and again the body note27 as just the body (not mine, not I, not self, but just a phenomenon) in himself; or he dwells perceiving again and again the body as just the body in others;note28 or he dwells perceiving again and again the body as just the body in both himself and in others.note29 He dwells perceiving again and again the cause and the actual appearing of the body; or he dwells perceiving again and again the cause and the actual dissolution of the body; or he dwells perceiving again and again both the actual appearing and dissolution of the body with their causes.note30 To summarize, he is firmly mindful of the fact that only the body exists (not a soul, a self or I). That mindfulness is just for gaining insight (vipassana) and mindfulness progressively. Being detached from craving and wrong views note31 he dwells without clinging to anything in the world.note32 Thus, bhikkhus, this is a way in which a bhikkhu dwells perceiving again and again the body as just the body.