Avesta word for "praise-song" (Bartholomae: "Lobgesang"); that word is not actually attested in any text. The surviving texts of the Avesta, as they exist today, derive from a single master copy produced by Sasanian Empire-era (224–651 CE) collation and recension. That master copy, now lost, is known as the 'Sassanian archetype'. The oldest surviving manuscript ("K1") of an Avestan language text is dated 1323 CE. Summaries of the various Avesta texts found in the 9th/10th century texts of Zoroastrian tradition suggest that a significant portion of the literature in the Avestan language has been lost. Only about one-quarter of the Avestan
Religion in Asia trying to destroy the creation of Mazda (asha), and good trying to sustain it. Mazda is not immanent in the world, and His creation is represented by the Amesha Spentas and the host of other Yazatas, through whom the works of God are evident to humanity, and through whom worship of Mazda is ultimately directed. The most important texts of the religion are those of the Avesta, of which a significant portion has been lost, and mostly only the liturgies of which have survived. The lost portions are known of only through references and brief quotations in the later works