The priests' practice of including commentaries alongside the text being commented upon led to two different misunderstandings in 18th/19th century western scholarship.
"Zend-Avesta" The first was the treatment of "Zend" and "Avesta" as synonyms and the mistaken use of "Zend-Avesta" as the name of Zoroastrian scripture. This mistake derives from a misunderstanding of the distinctions made by priests between manuscripts for scholastic use ("Avesta-
with-Zand"), and manuscripts for liturgical use ("clean"). In western scholarship, the former class of manuscripts was misunderstood to be the proper name of the texts, hence the misnomer "Zend-Avesta" for the Avesta. In priestly use, however, "Zand-i-Avesta" or "Avesta-o-Zand" merely identified manuscripts that are not suitable for ritual use since they are not "clean" (''sa'deh'') of non-Avestan elements.
"Zend" as the name of a language The second mistaken use of the term
Zend was its use as the name of a language or script. In 1759,
Anquetil-Duperron reported having been told that
Zend was the name of the language of the more ancient writings. Similarly, in his third discourse, published in 1798,
Sir William Jones recalls a conversation with a Hindu priest who told him that the script was called
Zend, and the language
Avesta. This mistake resulted from a misunderstanding of the term
pazend, which actually denotes the use of the
Avestan alphabet for writing certain Middle Persian texts.
Rasmus Rask's seminal work,
A Dissertation on the Authenticity of the Zend Language (Bombay, 1821), may have contributed to the confusion. Propagated by N. L. Westergaard's
Zendavesta, or the religious books of the Zoroastrians (Copenhagen, 1852–54), by the early/mid 19th century, the confusion became too universal in Western scholarship to be easily reversed, and
Zend-Avesta, although a misnomer, continued to be fashionable well into the 20th century. == List of Zands ==