YASNA is the name given to the 72 holiest hymns, the foremost god invocations in the Zoroastrian worship.
The word Yasná comes from the root yas/ya and means “intense desire, fervent wish, yearning.” The ancient commentary translates it as xvastan.
Yasná is etymologically related to Tocharian yask, Greek zêlos, Latin zelus “intensity, fervor, burning desire.”
Yásá/Yáßá is the 2nd word in the poetic gathas; I fervently desire/yearn (for the very prize of ahûrmazd’s own self) through numinous prayers/formulas (See Yasna 28.1.)
The poetic gathas also conclude with “intense longing” in the famous Airyemá Ishyö formula; I yearn for the riches of excellence/virtue, the wished-for *mind power of mazdá ahûrá (See Yasna 54. 4th rhymed verse line.)
*Masatá/Maßatá is “the mind power to think, conceive, formulate, create.” The ancient commentary plays on a skillful word play here and translates it as “maximize.” Thus the intense longing/burning wish yas of the noble or Aryan fellowship Airyemá Ishyö is to become like mazdá ahûrá through “the powers of mind/spirit” and maximize godhood.
In the Vársht-mánßar commentary of Yasna 33.6, ahûrmazd creates the worlds through yasná “fervent wish, desire, intensity of the spirit.” And at the time of the fresh, new, creation of the worlds, Zarathûshtrá officiates as züt “the invoker of god-powers” at the yasná ceremony that will set in the eternal progress of the worlds.
In Zoroastrianism, thinking powers are gods in making. Yasná is the burning desire to manifest in eternity and infinity. Yasná is the longing and intensity of the spirit to become a god being through the wondrous odyssey of mind power.
The Yasna ceremony reenacts the primeval power of “manifestation, creation through fervent wish/desire.” The preparation of the sacred drink and/or wine of immortality haômá, the holy bread drön, the offering of milk and the evergreen branches barsôman, all remind one of the pagan origins of the Catholic Mass that resembles the Yasna ceremony to a great degree.
Yasna ceremony is performed in the early pre dawn hours. The ritual is only conducted by qualified priests in a designated sacred space of utmost purity.
The names of the eight priests are preserved in Avestan as zaôtar “invoker of god-powers,” hávanán, ásnatar, átrə-vaxš, sraôšā-varəz, ábərət, frabərətar, ráθvîš (Vedic ṛtvíj) knower of rites.
Today the eight priests of the ancient yasna are reduced in number to two (zöt Avestan zaôtar “invoker of god powers” and ráspîg, Avestan ráθvîš “knower of rites.”
The sacred space is oriented on a north/south axis. There is a raised stone seat for the zöt “invoker” at the north end facing south, in front of which is the main stone table, on which are mortar and pestle for the pounding of the höm plant, two holders for the barsôman (evergreen branches), a knife, filter, and various cups for holding spring water (áb) and libations (zöhr); also present are the haômá twigs, a pomegranate, and whole milk.
To the south is the fire-stand with small tables to the west for kindling wood and incense, near which the rāspīg “knower of rites” takes his stand. To the west of the main table is another table for other water vessels. Both priests must be in a state of complete physical and spiritual purity.
The Yasna drön bread is identical to Catholic Eucharist. Parsi priests place clarified butter, representing the gôšodáy (Avestan gaôš.hû-δáv), in the center of the drön and consecrate them together.
The holy unleavened bread is a replacement for the flesh offering and animal sacrifice.
An issue that seems to have been at the center of Zarathustra’s reform of ritual was animal sacrifice, and the violence and cruelty visited upon the innocent animal victim.
The Aryan Prophet saw animal sacrifice as on abominable misdeed that only pleased demonic powers or daævás (See especially Yasna 29; also the sacrifice of the Vyámbûra-daævas, Yt. 14.54-56.)
Zarathustra’s clear opposition to cruelty of animal sacrifice has led some modern scholars to erroneously believe that he forbade haômá or the elixir of immortality (See Yasna 34.11, 1st rhymed verse line.)
What the ancient seer/prophet abhorred was the blood sacrifice associated with the pressing of haômá nectar. He struck a violent blow at the filth of blood libations and removed them from the preparation of the elixir or wine of immortality (See Yasna 48.10, 2nd rhymed verse line.)
In conclusion, I like to add that sacred number 72 is the sum total chapters of Yasna. The number 72 equals 3 times 24 or the number of the chapters of vispa-ratö “all the wise counsels or knowers of riddles.”
Yasna invokes the 33 god powers or giver of boons. The performance of 72 Yasnas in each of the 5 holy gatha or song days, amounts to 360 or the number of days in the Zoroastrian religious year.
The daily performance of 72 Yasna in each 360 days amounts to 25920, the number of years it takes for one full cycle of the equinoxes around the axis of the ecliptic. (See Gernot Windfuhr on Yasna ritual)