Zend or Zand is a Zoroastrian technical term for exegetical glosses, paraphrases, commentaries and translations of the Avestas texts. The term zand is a contraction of the Avestan language word zainti, meaning "interpretation", or "as understood". Zand glosses and commentaries exist in several languages, including in the Avestan language itself. These Avestan language exegeses sometimes accompany the original text being commented upon, but are more often elsewhere in the canon. An example of exegesis in the Avestan language itself includes Yasna 19-21, which is a set of three Younger Avestan commentaries on the three Gathic Avestan 'high prayers' of Yasna 27. Zand also appear to have once existed in a variety of Middle Iranian languages, but of these Middle Iranian commentaries, the Middle Persian zand is the only to survive fully, and is for this reason regarded as 'the' zand. With the notable exception of the Yashts, almost all surviving Avestan texts have their Middle Persian zand, which in some manuscripts appear alongside (or interleaved with) the text being glossed. The practice of including non-Avestan commentaries alongside the Avestan texts led to two different misinterpretations in western scholarship of the term zand; these misunderstandings are described below. These glosses and commentaries were not intended for use as theological texts by themselves but for religious instruction of the (by then) non-Avestan-speaking public. In contrast, the Avestan language texts remained sacrosanct and continued to be recited in the Avestan language, which was considered a sacred language. The Middle Persian zand can be subdivided into two subgroups, those of the surviving Avestan texts, and those of the lost Avestan texts.