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Yasna (Avestan for 'oblation' or 'worship') is the name of the primary liturgical collection of texts of the Avesta as well as the name of the principal Zoroastrian act of worship at which those verses are recited. The Yasna, or Izeshne, is primarily the name of the ceremony in which the entire book is recited and appropriate liturgical actions performed. In its normal form, this ceremony can only be performed in the morning.
A well-trained priest is able to recite the entire Yasna in about two hours. (Stausberg, 2004:337,n131) With extensions, it takes about an hour longer. Yasna chapter and verse pointers are traditionally abbreviated with Y.
The service 
The Yasna service, that is, the recitation of the Yasna texts, culminates in the Ab-Zohr, the "offering to waters". The Yasna ceremony may be extended by recitation of the Visperad and Vendidad.
As the name of the service, the term Yasna is linguistically (but not functionally) cognate with Vedic Yajna. Unlike Vedic Yajna, Zoroastrian Yasna has "to do with water rather than fire" (Drower, 1944:78; Boyce, 1975:147-191)
The liturgy 
The texts of the Yasna are organized into 72 chapters, also known as hads or has (from Avestan ha'iti, 'cut'). The 72 threads of the Zoroastrian Kusti the sacred girdle worn around the waist - represent the 72 chapters of the Yasna. The collection includes the 17 chapters of the Gathas, the oldest and most sacred texts of the Zoroastrian canon.
Some sections of the Yasna occur more than once. For instance, Yasna 5 is repeated as Yasna 37, and Yasna 63 consists of passages from Yasna 15.2, 66.2 and 38.3. The ability to recite the Yasna from memory is one of the prerequisites for Zoroastrian priesthood.
Content and organization 
- Yasna 1 opens with the praise of Ahura Mazda, enumerating his divine titles as the Creator, "radiant, glorious, the greatest, the best, the most beautiful, the most firm, the most wise, of the most perfect form, the highest in righteousness, possessed of great joy, creator, fashioner, nourisher, and the Most Holy Spirit." (Dhalla, 1936:155). Yasna 1 then enumerates the divinities, inviting them to the service.
- Yasna 2, the Barsom Yasht, presents libation and the barsom (a bundle of 23 twigs bound together, symbolizing sanctity) to the invited divinities. Yasna 2-4 complement Yasna 1. Most verses in Yasna 2-3 begin with the formula ayese yeshti …, "by means of this sacrifice, I call …", followed by the name of the divinity being invoked.
- Yasna 3-8 known collectively as the Sarosh dron, presents other offerings (zaothra). Yasna 3 draws the attention of the divinities invoked in Yasna 1, and in Yasna 4, the offerings are consecrated to the divinities. Yasna 5 is repeated in Yasna 37. Yasna 6 is almost identical to the first 10 verses of Yasna 17.
- Yasna 9-11 is the Hom Yasht, a collection of eulogies to the Haoma plant and its divinity.
- Yasna 12 constitutes the Fravarane, the Zoroastrian creed and declaration of faith. It is in "Artificial" Gathic Avestan, that is, it is stylistically and linguistically aligned with the language of the Gathas, but imperfectly. The last strophe of verse 7 as well as all of verses 8 and 9 are incorporated into the Kusti ritual.
- Yasna 13-18 are comparable to Yasna 1-8 in that they too are a collection of invocations to the divinities. Chapters 14-18 serve as an introduction to the Staota Yesniia of Yasna 19-59. The first 10 verses of Yasna 17, "to the fires, waters, plants", is almost identical to Yasna 6.
- Yasna 19-21, the Bhagan Yasht, are commentaries on the three 'high prayers' of Yasna 28-53.
- Yasna 22-26 is another set of invocations to the divinities.
- Yasna 27 has the prayers referred to by Yasna 19-21. These are:
- The Ahuna Vairya invocation (also known as the Yatha Ahu Vairyo), the most sacred of all Zoroastrian prayers.
- The Ashem Vohu
- The Yenghe hatam
- Yasna 28-53 include the (linguistically) oldest texts of the Zoroastrian canon. 17 of the 26 chapters make up the Gathas, the most sacred hymns of Zoroastrianism and thought to have been composed by Zoroaster himself. The Gathas are in verse. These are structurally interrupted by a) the Yasna Haptanghaiti ("seven-chapter Yasna", #35-41), which is as old as the Gathas but in prose, b) two short chapters (#42 and #52) that are not as old as the Gathas and Yasna Haptanghaiti.
- Yasna 55 is a praise to the Gathas and the Staota Yesniia.
- Yasna 56 is again an invocation to the divinities, appealing for their attention.
- Yasna 57 is the Sarosh Yasht, the hymn to the divinity of religious discipline. It is closely related to, and appears to have sections borrowed from Yasht 10, the hymn to Mithra.
- Yasna 58 is again a "hidden" Yasht, here to the genius of prayer (cf. Dahman).
- Yasna 59 is a repetition of the sections from Yasna 17 and 26.
- Yasna 60 is blessing upon the house of the ashavan ('just' or 'true' man). Yasna 60.2-7 constitute the Dahma Afriti invocation, also known as the Afrinagan Dahman.
- Yasna 61 praises the anti-demonic powers imbued in the Afrinagan Dahman, Yenghe hatam and the three principal prayers of Yasna 27.
- Yasna 62 constitutes the Ataksh Nyashes, prayers to fire and its divinity.
- Yasna 63-69 constitute the prayers that accompany the Ab-Zohr, "offering to water".
- Yasna 70-72 are again a set of invocations to the divinities.
External links 
- Translations of the Yasna liturgy now in the public domain:
- Complete YASNA