1. The Zoroastrian Kasti prayers are actually composed in two languages, Avesta and Pazand. However the Avesta language is further sub-divided into two distinct and fairly different dialects – Gathic Avesta and standard Avesta. Thus the Kasti prayers are made up of the Pazand language as well as two dialects of Avesta language.
2. The Ashem vohu, Yatha ahu vairyo and much of the Kem na Mazda is composed of Gathic Avesta. Kem na Mazda has two stanzas from Ushtavaiti Gatha, and also has a passage from the Vendidad, which belongs to the other Avestan dialect.
3. The Ahura Mazda Khodai prayer is entirely in the Pazand language, but there are a few lines at the end in standard Avesta. The Jasa me Avanghe Mazda prayer is entirely in the standard Avestan language.
4. The Kasti prayers were compiled in fourth century AC during the Sasanian times by Dastur Adarbad Mahrespand, by selecting prayers from the Gathas, Yasna and the Vendidad.