The temple is an even later development: from Herodotus it is known that in the mid-5th century BCE the Zoroastrians worshipped to the open sky, ascending mounds to light their fires. In the oldest passages of that liturgy, it is the hearth fire that speaks to 'all those for whom it cooks the evening and morning meal', which Boyce observes is not consistent with sanctified fire. That the rituals of fire was a doctrinal modification and absent from early Zoroastrianism is also evident in the later Atash Nyash. There is no allusion to a temple of fire in the Avesta proper, nor is there any Old Persian language word for one. It appears at approximately the same time as the shrine cult and is roughly contemporaneous with the introduction of Atar as a divinity. First evident in the 9th century BCE, the Zoroastrian rituals of fire are contemporary with that of Zoroastrianism itself.
