Ānāpānasati Sutta

The Ānāpānasati Sutta or Ānāpānasmṛti Sūtra, "Breath-Mindfulness Discourse," Majjhima Nikaya 118, is a discourse that details the Buddha's instruction on using awareness of the breath as an initial focus for meditation.
The sutta includes sixteen steps of practice, and groups them into four tetrads, associating them with the four satipatthanas. According to American scholar monk, Thanissaro Bhikkhu, this sutta contains the most detailed meditation instructions in the Pali Canon.

Versions of the text

Theravada Pali Canon

The Theravada Pali Canon version of the Anapanasati Sutta lists sixteen steps to relax and compose the mind and body. The Anapanasati Sutta is a celebrated text among Theravada Buddhists. In the Theravada Pali Canon, this discourse is the 118th discourse in the Majjhima Nikaya and is thus frequently represented as "MN 118". In addition, in the Pali Text Society edition of the Pali Canon, this discourse is in the Majjhima Nikaya 's third volume, starting on the 78th page and is thus sometimes referenced as "M iii 78".

Summary of the Pali Canon version

Benefits

The Buddha states that mindfulness of the breath, "developed and repeatedly practiced, is of great fruit, great benefit." It fulfills the Four Foundations of Mindfulness. When these are developed and cultivated, they fulfill the Seven Factors of Enlightenment. And when these are developed and cultivated,
they fulfill "knowledge and freedom", "true knowledge and deliverance", or "clear vision and deliverance".

Establishing mindfulness

To develop and cultivate mindfulness of breathing, a monk goes to the wilderness or forest, or to the root of a tree, or to an empty hut, sits down with crossed legs and the body erect, and establishes mindfulness in front or right there, and mindfully breathes in and out.

Four tetrads

The Ānāpānasati Sutta then describes the monitoring of the breath, and relates this to various experiences and practices. Following the classification of the four satipatthanas, these experiences and practices are grouped into a list of sixteen objects or steps of instructions, generally broken into four tetrads. These core sixteen steps are one of the most widely taught meditation instructions in the early Buddhist texts. They appear in various Pali suttas like the Ananada sutta, not just the Anapanasati sutta. They also appear in various Chinese translations of the Agamas with minor differences as well as in the Vinayas of different schools. They are as follows:

First Tetrad: Contemplation of the Body
#Breathing in long he knows 'I am breathing in long.'

Breathing in short he knows 'I am breathing in short.'

#Breathing out long he knows 'I am breathing out long.'

Breathing out short he knows 'I am breathing out short.'

#He trains himself 'breathing in, I experience the whole body'.

'breathing out, I experience the whole body.'

#He trains himself, 'breathing in, I calm the bodily formation.'

'breathing out, I calm the bodily formation.'

Second Tetrad: Contemplation of the Feeling
#He trains himself, 'I will breathe in experiencing joy.'

He trains himself, 'I will breathe out experiencing joy.'

#He trains himself, 'I will breathe in experiencing pleasure.'.

He trains himself, 'I will breathe out experiencing pleasure.'

#He trains himself, 'I will breathe in experiencing mental formation.'

He trains himself, 'I will breathe out experiencing mental formation.'

#He trains himself, 'I will breathe in calming the mental formation.'

He trains himself, 'I will breathe out calming the mental formation.'

Third Tetrad: Contemplation of the Mind
#He trains himself, 'I will breathe in experiencing the mind.'

He trains himself, 'I will breathe out experiencing the mind.'

#He trains himself, 'I will breathe in pleasing the mind.'

He trains himself, 'I will breathe out pleasing the mind.'

#He trains himself, 'I will breathe in concentrating the mind.'

He trains himself, 'I will breathe out concentrating the mind.'

#He trains himself, 'I will breathe in releasing the mind.'

He trains himself, 'I will breathe out releasing the mind.'

Fourth Tetrad: Contemplation of the Mental Objects
#He trains himself, 'I will breathe in observing impermanence.'

He trains himself, 'I will breath out observing impermanence.'

#He trains himself, 'I will breathe in observing dispassion.'

He trains himself, 'I will breath out observing dispassion.

#He trains himself, 'I will breathe in observing cessation.'

He trains himself, 'I will breath out observing cessation.'

#He trains himself, 'I will breathe in observing relinquishment.'

He trains himself, 'I will breath out observing relinquishment.'

Seven factors of awakening

The sutra then explains how the four tetrads are correlated to the four satipatthanas. Next, the sutra explicates how contemplation of the four satipatthanas sets in the seven factors of awakening, which bring "clear knowing" and release.

In East Asian Buddhism

The Ānāpānasmṛti Sūtra, as the text was known to Sanskritic early Buddhist schools in India, exists in several forms. There is a version of the Ānāpānasmṛti Sutra in the Ekottara Āgama preserved in the Chinese Buddhist canon. This version also teaches about the Four Dhyānas, recalling past lives, and the Divine Eye. The earliest translation of Ānāpānasmṛti instructions, however, was by An Shigao as a separate sutra in the 2nd century CE. It is not part of the Sarvastivada Madhyama Āgama, but is instead an isolated text, although the sixteen steps are found elsewhere in the Madhyama and Samyukta Āgamas. The versions preserved in the Samyukta Agama are SA 815, SA 803, SA 810–812 and these three sutras have been translated into English by Thich Nhat Hanh.

Related canonical discourses

Breath mindfulness, in general, and this discourse's core instructions, in particular, can be found throughout the Pali Canon, including in the "Code of Ethics" as well as in each of the "Discourse Basket" collections. From these other texts, clarifying metaphors, instructional elaborations and contextual information can be gleaned. These can also be found throughout the Chinese Agamas.

Pali suttas including the core instructions

In addition to being in the Anapanasati Sutta, all four of the aforementioned core instructional tetrads can also be found in the following canonical discourses:

the "Greater Exhortation to Rahula Discourse" ;
sixteen discourses of the Samyutta Nikaya's chapter 54 : SN 54.1, SN 54.3-SN 54.16, SN 54.20;
the "To Girimananda Discourse" ; and,
the Khuddaka Nikaya's Patisambhidamagga's section on the breath, Anapanakatha.

The first tetrad identified above can also be found in the following discourses:

the "Great Mindfulness Arousing Discourse" and, similarly, the "Mindfulness Arousing Discourse", in the section on Body Contemplation; and,
the "Mindfulness concerning the Body Discourse" as the first type of body-centered meditation described.

Chinese sutras with the core steps

The Saṃyukta Āgama contains a section titled Ānāpānasmṛti Saṃyukta which contains various sutras on the theme of anapanasati including the sixteen steps.

Metaphors

Hot-season rain cloud

In a discourse variously entitled "At Vesali Discourse" and "Foulness Discourse", the Buddha describes "concentration by mindfulness of breathing" in the following manner:
After stating this, the Buddha states that such an "ambrosial pleasant dwelling" is achieved by pursuing the sixteen core instructions identified famously in the Anapanasati Sutta.

The skillful turner

In the "Great Mindfulness Arousing Discourse" and the "Mindfulness Arousing Discourse", the Buddha uses the following metaphor for elaborating upon the first two core instructions:

Expanded contexts

Great fruit, great benefit

The Anapanasati Sutta refers to sixteenfold breath-mindfulness as being of "great fruit" and "great benefit". "The Simile of the Lamp Discourse" states this as well and expands on the various fruits and benefits, including:

unlike with other meditation subjects, with the breath one's body and eyes do not tire and one's mind, through non-clinging, becomes free of taints
householder memories and aspirations are abandoned
one dwells with equanimity towards repulsive and unrepulsive objects
one enters and dwells in the four material absorptions and the four immaterial absorptions
all feelings are seen as impermanent, are detached from and, upon the death of the body, "will become cool right here."

Commentaries and interpretations

Traditional commentaries

Pali commentaries

In traditional Pali literature, the 5th-century CE commentary for this discourse can be found in two works, both attributed to Ven. Buddhaghosa:

the Visuddhimagga provides commentary on the four tetrads, focusing on "concentration through mindfulness of breathing".
the Papañcasūdanī provides commentary on the remainder of this discourse.

The earlier Vimuttimagga also provides a commentary on Anapanasati, as does the late canonical Pali Paṭisambhidāmagga.
Likewise, the sub-commentary to the Visuddhimagga, Paramatthamañjusā, provides additional elaborations related to Buddhaghosa's treatment of this discourse. For instance, the Paramatthamañjusā maintains that a distinction between Buddhists and non-Buddhists is that Buddhists alone practice the latter twelve instructions described in this sutta: "When outsiders know mindfulness of breathing, they only know the first four modes ".

Sanskrit commentaries

The Śrāvakabhūmi chapter of the Yogācārabhūmi-śāstra and Vasubandhu's Abhidharmakośa both contain expositions on the practice outlined in the Ānāpānasmṛti Sūtra.

Chinese commentaries

The Chinese Buddhist monk An Shigao translated a version of the Ānāpānasmṛti Sūtra into Chinese known as the Anban shouyi jing as well as other works dealing with Anapanasati. The practice was a central feature of his teaching and that of his students who wrote various commentaries on the sutra.
One work which survives from the tradition of An Shigao is the Da anban shouyi jing which seems to include the translated sutra of anapanasmrti as well as original added commentary amalgamated within the translation.

Modern interpretations

According to Ajahn Sujato, the ultimate goal of Anapanasati is to bear insight and understanding into the Four Foundations of Mindfulness, the Seven Factors of Awakening, and ultimately Nibbana.
Different traditions interpret a number of aspects of this sutta in different ways. Below are some of the matters that have multiple interpretations:

Are the 16 core instructions to be followed sequentially or concurrently ?
Must one have reached the first jhana before pursuing the second tetrad ?
In the preparatory instructions, does the word "parimukham" mean: around the mouth, in the chest area, in the forefront of one's mind or simply "sets up mindfulness before him" or "to the fore" or "mindfulness alive" ?
In the first tetrad's third instruction, does the word "sabbakaya" mean: the whole "breath body" or the whole "flesh body", and the commentary, which explains that the "body among bodies" refers to the wind element as opposed to other ways of relating to the body?

Modern expositions available in English

Analayo. Understanding and Practicing the Ānāpānasati-sutta in "Buddhist Foundations of Mindfulness" 1st ed. 2015 Edition
Buddhadasa. Santikaro Bhikkhu. Mindfulness with Breathing: A Manual for Serious Beginners. Wisdom Publications; Revised edition..
Bhaddanta Āciṇṇa.
Bhante Vimalaramsi.
Thanissaro Bhikkhu. . 2012.
U. Dhammajīva Thero.
Upul Nishantha Gamage.
Ajahn Kukrit Sotthibalo.