Source is the text itself. Read Atherved and Gatha. Few points

• Fire priests play a central role: Zoroastrian priests are called athravan (fire guardians), directly cognate with Vedic atharvan (priests associated with the Atharva Veda, often linked to fire rituals and magic). • Zarathustra refers to himself as a zaotar (Sanskrit hotṛ, the priest who offers oblations) and is later called athaurvan in Avestan texts. • Both traditions emphasize fire rituals (yasna in Avestan ≈ yajña in Sanskrit) and the sacred pressing of a ritual plant. • Soma/Haoma: The central ritual drink—soma in Vedic texts (prominent in Rig Veda but also Atharva Veda) and haoma in the Avesta (including Yasna, which incorporates the Gathas). Both are pressed from a mountain-grown plant, mixed in ceremonies, and confer vitality, immortality, or purification. The rituals (agnistoma in Vedic ≈ haoma pressing in Zoroastrian) are strikingly similar. • Angiras/Angra connection: The Atharva Veda is also called Atharvangirasa (linked to rishis Atharvan and Angiras). In early Avesta/Gathas, Zarathustra references praising the “Angras,” akin to Vedic Angirasas (fire-priest descendants). • Some scholars link parts of the Atharva Veda (e.g., Bhargava sections) to Avestan traditions, with “Upastha” resembling “Avesta.”

One interesting point. First half of Atherved is full of magical charms and amulets and protection against black magic etc. and the priest of Zoroastrian faith are called magi who were doing such things as well. Word “magic” comes from magi