'mindfulness on in-and-out-breathing', 

is one of the most important exercises for reaching mental concentration and the 4 absorptions (jhāna, q.v.).

In the Satipatthāna Sutta (M. 10, D. 22) and elsewhere, 4 methods of practice are given, which may also serve as basis for insight meditation. The 'Discourse on Mindfulness of Breathing' (ānāpānasati Sutta, M. 118) and other texts have 16 methods of practice, which divide into 4 groups of four. The first three apply to both tranquillity (samatha, q.v.) and insight-meditation, while the fourth refers to pure insight practice only. The second and the third group require the attainment of the absorptions.

"With attentive mind he breathes in, with attentive mind he breathes out.

I. (1) "When making a long inhalation he knows: 'I make a long inhalation'; when making a long exhalation he knows: 'I make a long exhalation.'

(2) "When making a short inhalation he knows: 'I make a short inhalation'; when making a short exhalation he knows: 'I make a short exhalation.'

(3) " 'Clearly perceiving the entire (breath-) body I will breathe in,' thus he trains himself; 'clearly perceiving the entire (breath-) body I will breathe out,' thus he trains himself.

(4) " 'Calming this bodily function I will breathe in,' thus he trains himself; 'calming this bodily function I will breathe out,' thus he trains himself.

II. (5) " 'Feeling rapture (pīti) I will breathe in,' thus he trains himself; 'feeling rapture I will breathe out,' thus he trains himself.

(6) " 'Feeling joy I will breathe in,' thus he trains himself; 'feeling joy I will breathe out,' thus he trains himself.

(7) " 'Feeling the mental construction (citta-sankhāra) I will breathe in,' thus he trains himself, 'feeling the mental construction I will breathe out,' thus he trains himself.

(8) " 'Calming the mental construction I will breathe in,' thus he trains himself; 'calming the mental construction I will breathe out,' thus he trains himself.

III. (9) " 'Clearly perceiving the mind (citta) I will breathe in,' thus he trains himself; 'clearly perceiving the mind I will breathe out,' thus he trains himself.

(10) " 'Gladdening the mind I will breathe in,' thus he trains himself; 'gladdening the mind I will breathe out,' thus he trains himself.

(11) " 'Concentrating the mind I will breathe in, thus he trains himself; 'concentrating the mind I will breathe out', thus he trains himself.

(12) " 'Freeing the mind I will breathe in,' thus he trains himself; 'freeing the mind I will breathe out,' thus he trains himself

IV. (13) " 'Reflecting on impermanence (anicca) I will breathe in,' thus he trains himself; 'reflecting on impermanence I will breathe out,' thus he trains himself.

(14) " 'Reflecting on detachment (virāga) I will breathe in,' thus he trains himself; 'reflecting on detachment I will breathe out,' thus he trains himself.

(15) " 'Reflecting on extinction (nirodha) I will breathe in,' thus he trains himself; 'reflecting on extinction I will breathe out,' thus he trains himself.

(16) " 'Reflecting on abandonment (patinissagga) I will breathe in, thus he trains himself; 'reflecting on abandonment I will breathe out,' thus he trains himself."

In M. 118 it is further shown how these 16 exercises bring about the 4 foundations of mindfulness (satipatthāna, q.v.), namely: 

• 1-4 contemplation of the body, 

• 5-8 contemplation of feeling, 

• 9-12 contemplation of mind (consciousness), 

• 13-16 contemplation of mind-objects.

•  Then it is shown how these 4 foundations of mindfulness bring about the 7 factors of enlightenment (bojjhanga, q.v.); then these again deliverance of mind (ceto-vimutti, q.v.) and deliverance through wisdom (paññā-vimutti, q.v.).

• Literature: Ānāpānasati Samyutta (S. LIV). - 

• Pts.M. Ānāpānakathā - Full explanation of practice in Vis.M. VIII, 145ff. - 

• For a comprehensive anthology of canonical and commentarial texts, see Mindfulness of Breathing, ñānamoli Thera (Kandy: BPS, 1964).