Tishtrya

Tishtrya (Persian: Tir) is the Zoroastrian Yazata of the star identified with Sirius, and the divine power behind the coming of the seasonal rains. His yasht — the eighth of the twenty — is one of the most narratively vivid in the whole collection, staging a cosmic battle for the water on which every living creature in Zoroastrian cosmology depends.

Tishtrya’s rise and the world’s longing

The Tishtar Yasht opens not with abstract praise but with anxious anticipation: “long flocks and herds and men” look for Tishtrya’s rising, asking “when shall we see him rise up, the bright and glorious star Tishtrya? When will the springs run with waves as thick as a horse’s size and still thicker? Or will they never come?” This framing — creation itself waiting on a single star’s return — establishes Tishtrya’s stakes before the narrative of his battle even begins.

The battle with Apaosha

Ten nights into his rising, Tishtrya “mingles his shape with light,” appearing as “a white, beautiful horse, with golden ears and a golden caparison,” and descends to the cosmic sea Vouru-Kasha to gather the rains. There “rushes down to meet him the Daeva Apaosha, in the shape of a dark horse, black with black ears, black with a black back, black with a black tail, stamped with brands of terror.” The two meet “hoof against hoof” and fight for three days and three nights — and at first Apaosha, the demon of drought, “proves stronger… he overcomes him.” Tishtrya’s own explanation for this defeat is theological rather than martial: he laments that men have not worshipped him “with a sacrifice in which I had been invoked by my own name,” and so lacked the strength that due honor would have given him.

Ahura Mazda’s intervention and Tishtrya’s victory

Ahura Mazda himself then offers the sacrifice Tishtrya was owed, bringing him “the strength of ten horses, the strength of ten camels, the strength of ten bulls, the strength of ten mountains, the strength of ten rivers.” Strengthened, Tishtrya returns to the sea and this time overcomes Apaosha by noon. His cry of victory follows immediately: “Hail unto me, O Ahura Mazda! Hail unto you, O waters and plants!… The life of the waters will flow down unrestrained to the big-seeded corn fields.” The Yasht then describes the vapors rising as clouds, driven by the wind “along the ways which Haoma traverses,” down to “the seven Karshvares of the earth” as rain.

Tishtrya and ritual dependency

The Tishtar Yasht’s theology is unambiguous about why the drought-demon nearly wins: Tishtrya’s cosmic strength is not automatic but is sustained by human sacrifice offered in his own name. The myth makes the ordinary Zoroastrian’s fidelity to ritual observance cosmically consequential — the rain that waters the “big-seeded corn fields” depends, in this account, on a chain running from the sacrifices offered at the fire to the strength of a star fighting a demon at the edge of the world’s sea.