This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The Saoshyant is not, in the oldest Zoroastrian texts, a single fixed person. Zarathustra's own hymns, the Gathas, use the word for any righteous helper whose deeds contribute to the world's renovation, sometimes in the plural. It is the Younger Avesta, above all Yasht 19, the Zamyad Yasht, that narrows the word into a coming individual and links him to the khvarenah, the divine glory that marks Iran's rightful rulers, now transferred to a saviour still to come.
The fullest version of the story belongs to the later Pahlavi literature, compiled centuries after the Avesta itself. There, Zarathustra's seed is said to be preserved miraculously in Lake Kansaoya, guarded until the appointed times. Three virgin mothers will bathe in the lake and each conceive a son at an interval of a thousand years: Ushedar, then Ushedarmah, and finally the Saoshyant, who completes what his two forerunners began. Each renews the world further; the last raises the dead, presides over a universal judgement in which a flood of molten metal purifies every soul, felt as burning by the wicked and as warm milk by the righteous, and brings about frashokereti, the final and permanent restoration of creation.
How much of this staged, three-saviour scheme reflects belief already current in the Achaemenid period and how much is Sasanian-era elaboration is genuinely debated, since the Pahlavi books that spell it out in detail postdate the events they describe by a wide margin. What is not in serious dispute is the doctrine's later reach: historians of religion widely read its resurrection, judgement and renewal as an influence, direct or parallel, on the end-time expectations of Judaism, Christianity and Islam.