The evening watch shows with particular clarity how the gah system knits together clock, cosmology and household economy. Its name derives from the Avestan for the coming of night's recitation, and its boundaries are practical ones, the disappearance of the sun and the middle of the night; between them fall the acts by which a pastoral and agricultural people closed its day. The Gah text itself blesses the increase of cattle and remembers the zaotar's evening duties, and the tradition's commentators read the watch as the daily meeting point of the living and their guardians: the herds safely folded, the family gathered at the fire, the fravashis of the ancestors present at the hearth that must never be allowed to die.
The hearth fire's continuous life, banked at night and revived at morning, is one of Zoroastrianism's oldest domestic disciplines, the household's small copy of the ever-burning temple fires, and its evening tending belonged to this watch, with the lamp-lighting prayers that parallel, in a wholly independent tradition, the lucernarium of the Christian evening and the lamp of the Jewish sabbath eve. Comparativists value the gah for exactly this: it preserves, in a still-living practice, the shape of an evening piety older than any of the book religions, in which nightfall is met not with fear alone but with an orderly muster, fire fed, cord retied, guardians greeted, before the household hands itself over to the watch of deep night that follows.