The one, more often chanted by Theravadin monks, is also referred to as Karaṇīyamettā Sutta after the opening word, Karaṇīyam, "(This is what) should be done." It is found in the Suttanipāta (Sn 1.8) and Khuddakapāṭha (Khp 9). It is ten verses in length and it extols both the virtuous qualities and the meditative development of mettā (Pali), traditionally translated as "loving kindness" or "friendliness." Additionally, Thanissaro Bhikkhu's translation, "goodwill", underscores that the practice is used to develop wishes for unconditional goodwill towards the object of the wish.
The other, also chanted by Theravadin Buddhist monks at times, extols the benefits of the practice of mettā (Pali) and it is found in the Anguttara Nikaya (AN 11.15). is also referred to as Mettānisamsa Sutta. This article will focus on the first version.
In Theravāda Buddhism's Pali Canon, mettā is one of the four "divine abodes" (Pali: brahmavihāra) recommended for cultivating interpersonal harmony and meditative concentration (see, for instance, kammaṭṭhāna).
According to post-canonical Sutta Nipāta commentary, the background story for the Mettā Sutta is that a group of monks were frightened by the sprites in the forest where the Buddha had sent them to meditate. When the monks sought the Buddha's aid in dealing with the sprites, the Buddha taught the monks the Mettā Sutta as an antidote for their fear. The monks recited the sutta and felt better. Their good cheer then happened to quiet the sprites as well.
The Mettā Sutta contains a number of recollections or recitations that promote the development of mettā through virtuous characteristics and meditation.
The discourse identifies fifteen moral qualities and conditions conducive to the development of mettā. These include such qualities as being non-deceptive (uju), sincere (suju), easy to correct (suvaco), gentle (mudu) and without arrogance (anatimānī).
In terms of meditative development, the discourse identifies:
- an intentional wish that facilitates generating mettā (Pali: sukhino vā khemino hontu; English: "May all beings be happy and safe")
- a means for developing meditational objects (a list of various sizes, proximity, etc.) for such a wish
- a metaphor — of a mother's protective love for her only child — for how one should cherish this meditation theme and guard it safely. (Note: this is often - indeed, almost universally - misinterpreted as a prototypical metaphor for the feeling we ought to cultivate toward others; however, this is not its intended meaning, as explained by Thanissaro Bhikkhu in the article "Metta Means Goodwill.")
- a method for radiating mettā outwards in all directions
- Brahmavihāra - for "divine abodes" identified by the Buddha, including metta.
- Ten paramis
- Paritta - traditional Buddhist "protective suttas," including this one.
- Translation from the excerpt at Metta#Karaniya Metta Sutta (Sn 1.8).
- Bodhi (2005a), pp. 90, 131, 134, passim; Gethin (1998), pp. 26, 30, passim [spelled as two words: "loving kindness"]; Harvey (2007), pp. 247-8 [spelled without a hyphen: "lovingkindness"]; Ñāṇamoli & Bodhi (2001), pp. 120, 374, 474, passim; Salzberg (1995), passim [without a hyphen]; Walshe (1995), p. 194; Warder (2004), pp. 63, 94.
- Kamalashila (1996); Rhys Davids & Stede (1921-25), p. 540, entry for "Mettā," (retrieved 2008-08-22 from "U. Chicago" at http://dsal.uchicago.edu/cgi-bin/philologic/getobject.pl?c.3:1:177.pali[permanent dead link]). Rhys Davids & Stede's complete list of general translations is "love, amity, sympathy, friendliness, active interest in others." See also Gunaratana (2007) who uses "loving-friendliness" based on the Pali word metta's being related to the Pali word mitta ("friend") and that, for Gunaratana, "kindness" is more akin to the Buddhist notion of karuna (compassion).
- "Metta Means Goodwill" at accesstoinsight.org
- See, e.g., Bodhi (2005b).
- Gunaratana (2007).
- See, e.g., Bodhi (2005b & 2005c).
- Bodhi, Bhikkhu (2005a). In the Buddha's Words: An Anthology of Discourses from the Pali Canon. Somerville, MA: Wisdom Publications. ISBN 0-86171-491-1.
- Bodhi, Bhikkhu (April 9, 2005b). "Sn 1.8 Mettā Sutta — Loving-kindness [part 1]" (lecture). Retrieved from "Bodhi Monastery" at  (mp3).
- Bodhi, Bhikkhu (April 23, 2005c). "Sn 1.8 Mettā Sutta — Loving-kindness (part 2)" (lecture). Retrieved from "Bodhi Monastery" at  (mp3).
- Gethin, Rupert (1998). The Foundations of Buddhism. Oxford: Oxford University Press. ISBN 0-19-289223-1.
- Gunaratana, Henepola (2007). "2007 Brahmavihara Retreat: The Karaniyametta Sutta, Introduction and Stanza One" (lecture). Retrieved from "Bhavana Society" at  (mp3).
- Harvey, Peter (2007). An Introduction to Buddhism: Teachings, History and Practices. Cambridge: Cambridge University Press. ISBN 0-521-31333-3.
- Kamalashila (1996). Meditation: The Buddhist Art of Tranquility and Insight. Birmingham: Windhorse Publications. ISBN 1-899579-05-2. Retrieveable from the author's personal web site at 
- Ñāṇamoli, Bhikkhu (trans.) & Bhikkhu Bodhi (ed.) (2001). The Middle-Length Discourses of the Buddha: A Translation of the Majjhima Nikāya. Boston: Wisdom Publications. ISBN 0-86171-072-X.
- Piyadassi Thera (ed., trans.) (1999). The Book of Protection: Paritta. Kandy: Buddhist Publication Society. Retrieved 08-14-2008 from "Access to Insight" at 
- Rhys Davids, T.W. & William Stede (eds.) (1921-5). The Pali Text Society’s Pali–English Dictionary. Chipstead: Pali Text Society. Retrieved 2008-08-22 from "U. Chicago" at 
- Salzberg, Sharon (1995). Lovingkindness: The Revolutionary Art of Happiness. Boston: Shambhala Publications. ISBN 1-57062-176-4.
- Walshe, Maurice (1995). The Long Discourses of the Buddha: A Translation of the Dīgha Nikāya. Somerville, MA: Wisdom Publications. ISBN 0-86171-103-3.
- Warder, A.K. (1970; reprinted 2004). Indian Buddhism. Motilal Banarsidass: Delhi. ISBN 81-208-1741-9.
- Translation of the Karaniya Metta Sutta
- Karaniya Metta Sutta read aloud (talking book) by Thanissaro Bhikkhu
- An Analysis of the Mettāsutta by Anandajoti Bhikkhu
- Anandajoti reading the Mettasutta translation in English
- Chandrabodhi chanting the Karaṇīyametta Sutta and other suttas in an 'Indian style'
- Sangharakshita reads the Karaṇīyametta and Mahāmangala-suttas, together with other readings from the Pali Canon
- Metta Sutta MP4