Literally, sutra means "sacred teachings".

    The sutra comprises discourses or sermons delivered by the Buddha at various times and places to his disciples. It is one of the Tripitaka (literally the Three Baskets), the canon of Buddhism. The Sutra Pitaka i.e. "Basket of Discourses" is essential teachings of Buddhism.

    41.1   The Six Fulfillment

    The Sutra is identified by its format known as the Six Fulfillment's. A sutra always begins with the words, "Thus have I heard. At one time ......." The sutra was complied by the disciple who recited from memory all the sermons in the First Council soon after the death of the Buddha. Therefore, The Six Fulfillment's are indication that it is the true record of the teaching given by the Buddha, and the words were coming out directly from the Buddha. Taking an example, the Diamond Sutra (or called the Vajra Paramita Sutra) begins with:

    1. "Thus" - the fulfillment of requirement on belief.
    2. "I have heard" - the fulfillment of requirement on hearing.
    3. "At one time" - the fulfillment of requirement on time.
    4. "The Buddha" - the fulfillment of requirement on the host, i.e. speaker.
    5. In Sravasti in the Jeta Grove of the Garden - the fulfillment of requirement on place.
    6. Together with a gathering of great Bhiksus, twelve hundred fifty in all - the fulfillment of requirement on audiences.

    This is the "common preface" of all Sutras.

    The sutras are dogmatic, which is the truth discovered by the Buddha in his enlightenment. Sutras are written in various figures of speech, chiefly simile and metaphor.

    41.2   The Five Nikayas (Agamas)

    There are five Nikayas ("collection of sutras", also call Agamas). The outline is as follows:

    1. Digha Nikaya (in Pali, Dirghagama in Sanskrit)
      "Collection of Long Discourses"

      34 long sutras subdivided into 3 groups. (Vaggas)

    2. Majjhima Nikaya (in Pali, Madhyamagama in Sanskrit)
      "Collection of Grouped Discourses"

      152 sutras subdivided into 15 groups. (Vaggas)

    3. Samyutta Nikaya (in Pali, Samyuktagama in Sanskrit)
      "Collection of Grouped Discourses"

      5 groups subdivided into 56 more groups.

    4. Anguttara Nikaya (in Pali, Ekottaragama in Sanskrit)
      "Collection of Discourses Treating Enumerations Classed in Ascending Order"

      This Nikaya is named because of the method of arranging the sutras. The first of eleven groups concerns lists of single things, the second concerns lists of two things, and so on up to the eleventh group. There are lists of eleven things discussed in this Nikaya.

    5. Khuddaka Nikaya (in Pali, Kukkutagama in Sanskrit)
      "Collection of Minor Works"

      There are 15 items in this Nikaya in Theravada:

      (1) Kuddaka-patha :   The Reading of short Passages.
      (2) Dhammapada :   Stanzas or Gatha on the Teaching.
      (3) Udana :   Solemn Utterances.
      (4) Itivuttaka :   Thus it is Said (from the introductory phrase to each sutra).
      (5) Sutra-nipata :   Collection of Sutras.
      (6) Vimana-vatthu :   Stories About Heavenly Palaces.
      (7) Peta-vatthu :   Stories About Hungry Ghosts.
      (8) Thera-gatha :   Verses of the Elders.
      (9) Theri-gatha :   Verses of the Nuns.
      (10) Jataka :   Previous Lives of the Buddha.
      (11) Niddesa :   Exposition.
      (12) Patisambhida-magga :   The Way of Analysis.
      (13) Apadana :   Verse Accounts of the Lives of Certain Monks and Nuns.
      (14) Buddhavamsa :   The Lineage of the Buddha.
      (15) Cariya-pitaka :   Collection Concerning Conduct.

      The first four Nikayas are recognized by all the early schools, but the fifth is found only in Pali and not in the Chinese translations. However, some sutras, such as Dharmapada exist in Chinese as separate scripture of other Agamas. In general, the sutras compared in early Buddhism are in Pali, representing the Theravada tradition, which is perhaps the only one form of Hinayana Buddhism nowadays.

    41.3   The Mahayana Sutra

    However, there are Mahayana sutras, which are probably composed over a period of several hundred years, as new insights developed in Mahayana. Presumably, the first Mahayana sutra is Prajna paramita sutra. Many other sutras are developed to expound the nature of a Buddha, the career of Bodhisattvas, the concepts of emptiness, the doctrine of Middle Way, etc., e.g.

    • The Prajnaparamita Sutra ("Sutra on Wisdom")
    • The Saddharmapundarika Sutra ("The Wonderful Dharma Lotus Flower Sutra").
    • The Avatamaska Sutra ("Flower Adnornment Sutra")
    • The Amitabha Sutra.

    Many Mahayana Sutras are related to numerous Buddhas and Bodhisattvas in the Dharma Realms.