The Avesta is a collection of the most sacred scriptures in Zoroastrianism, containing the teachings of the prophet, Zarathustra (Gk. Zoroaster). The original, written form is in the Avestan language (an eastern Indo-European language). However, its contents were most likely orally transmitted before being written down during the 3rd to 7th centuries in Iran.
First translated from Avestan and introduced to Europeans in 1771, it’s still used by Iranian Gabars and Indian Parsees.
The Avesta is mostly read to instill a sense of personal religious duty to the Lord (Ahura Mazda). As such, its style roughly compares to a combination of the Hindu Rig Veda and Book of Manu. Within the text Zarathustra dialogues with Ahura Mazda, asking questions and receiving answers on practical, cosmological and soteriological issues.
The theme of physical and spiritual pollution enters prominently in the Avesta, extending to both corpses and women during the menstrual period. Evil spiritual beings – “fiends” – are said to haunt the dakmas (graves or exposure sites known as “towers of silence”) and from their feeding create a stench.
Ahura Mazda tells Zarathustra,
The fiends revel in there until that stench is rooted in the Dakhmas. Thus from the Dakhmas arise the infection of diseases, itch, hot fever, humours, cold fever, rickets, and hair untimely white. There death has most power on man, from the hour when the sun is down.¹
These diseases tend to beset evil people who do not try to improve their ways.
As in many ancient cultures, including India and Greece, sickness and disease are attributed to the influence of the Evil One (Angra Mainyu) and his various demons.
At one point in the Avesta narrative, Zarathustra enters into battle with the fearsome Angra Mainyu, to emerge victorious. The resulting invocations and praises to various deities (all subservient to Ahura Mazda) again reveals that the Avesta is very much influenced by – and yet different from – the Hindu Rig Veda.
Although the Avesta is traditionally believed to have been revealed to Zarathustra, most scholars claim that only the Gathas, a group of 17 hymns, were authored by the prophet. While sections of the original text survive, much has been lost over the centuries.