In Eschatology and Soteriology
In addition to the role of fire as the agent of Truth, fire, among its various other manifestations, is also "the fire of judicial ordeal, prototype of the fiery torrent of judgement day, when all will receive their just deserts 'by fire and by Aša' (Y 31.3)"
In the Avesta, the "radiant quarters" of aša is "the best existence", i.e. Paradise (cf. Vendidad 19.36), entry to which is restricted to those who are recognized as "possessing truth" (ašavan). The key to this doctrine is Yasna 16.7: "We worship the radiant quarters of Aša in which dwell the souls of the dead, the Fravašis of the ašavans; the best existence (=Paradise) of the ašavans we worship, (which is) light and according all comforts."
'Aša' derives from the same Proto-Indo-European root as 'Airyaman', the divinity of healing who is closely associated with Asha Vahishta. At the last judgement, the common noun airyaman is an epithet of the saoshyans, the saviours that bring about the final renovation of the world. The standing epithet of these saviour figures is 'astvatәrәta', which likewise has arta as an element of the name. These saviours are those who follow Ahura Mazda's teaching "with acts inspired by aša" (Yasna 48.12). Both Airyaman and Asha Vahishta (as also Atar) are closely associated with Sraosha " Conscience" and guardian of the Chinvat bridge across which souls must pass.
According to a lost Avestan passage that is only preserved in a later (9th century) Pahlavi text, towards the end of time and the final renovation, Aša and Airyaman will together come upon the earth to do battle with the Az, the demon of greed (Zatspram 34.38-39).
The third Yasht, which is nominally addressed to Asha Vahishta, is in fact mostly devoted to the praise of the airyaman ishya (airyәmā īšyo, "Longed-for airyaman"), the fourth of the four great Gathic prayers. In present-day Zoroastrianism it is considered to invoke Airyaman just as the Ashem Vohu, is the second of the four great Gathic prayers, is dedicated to Aša. All four prayers (the first is the Ahuna Vairya, the third is the Yenghe Hatam) have judgement and/or salvation as a theme, and all four call on the Truth.
It is Airyaman that – together with fire – will "melt the metal in the hills and mountains, and it will be upon the earth like a river" (Bundahishn 34.18). In Zoroastrian tradition, metal is the domain of Xshathra, the Amesha Spenta of " Dominion", with whom Aša is again frequently identified. Dominion is moreover "a form of truth and results from truth."
In Denkard 8.37.13, Asha Vahishta actually takes over Airyaman's healer role as the healer of all spiritual ills and Airyaman then only retains the role of healer of corporeal ills. Although Airyaman has no dedication in the Siroza, the invocations to the divinities of the Zoroastrian calendar, Airyaman is twice invoked together with Aša. (Siroza 1.3 and 2.3)
Aogemadaecha 41-47 prototypes death as a journey that has to be properly prepared for: As mortals acquires material goods as they go through life, so also should they furnish themselves with spiritual stores of righteousness. They will then be well provisioned when they embark on the journey from which they will not return.
Aša's role is not limited to judgement: In Bundahishn 26.35, Aša prevents demons from exacting too great a punishment to souls consigned to hell. Here, Aša occupies the position that other texts assign to Mithra, who is traditionally identified with fairness.
For the relationship between Aša, eschatology and Nowruz, see in the Zoroastrian calendar, below.
Although there are numerous eschatological parallels between Aša and Aši "recompense, reward" (most notably their respective associations with Sraosha and Vohu Manah), and are on occasion even mentioned together (Yasna 51.10), the two are not etymologically related. The feminine abstract noun aši/arti derives from ar-, "to allot, to grant." Aši also has no Vedic equivalent.
Read more about this topic: Asha