Zend of Zand (Middel Perzisch: 𐭦�𐭣😂) is een zoroastrische diepzinnige term voor exegetische glossen, parafrasen, commentaren en vertalingen van de teksten van de Avesta. De term zand is een samentrekking van het woord in de Avestaanse taal zak (𐬰𐬀𐬌𐬥𐬙𐬌, wat “interpretatie” of “zoals begrepen” betekent).

Zand glosses and commentaries exist in several languages, including in the Avestan language itself. These Avestan language exegeses sometimes accompany the native text innate commented upon, but are more often elsewhere in the canon. An example of exegesis in the Avestan language itself includes Jasna 19–21, een reeks van drie commentaren op de Jongere Avestische Kerk over de drie Gathische Avestische ‘hoge gebeden’ van Jasna 27. Zand also appears to have next existed in a variety of Middle Iranian languages, but of these Middle Iranian commentaries, the Middle Persian zand is the isolated one to survive fully, and is for this explanation regarded as ‘the’ zand.

Met de opmerkelijke uitzondering van de Jassen, bijna alle overgebleven Avestaanse teksten hebben hun Middel-Perzische zand, which in some manuscripts appear alongside (or interleaved with) the text monster glossed. The practice of including non-Avestan commentaries contiguously the Avestan texts led to two oscillate misinterpretations in western scholarship of the term zand; these misunderstandings are described below. These glosses and commentaries were not designed for use as theological texts by themselves but for religious guidance 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 unshakable Avestan texts, and those of the directionless Avestan texts.

Een consistente exegetische procedure is duidelijk zichtbaar in manuscripten waarin de originele Avestan en zijn zand coexist. The priestly scholars first translated the Avestan as literally as possible. In a second step, the priests then translated the Avestan idiomatically. In the total step, the idiomatic translation was complemented subsequent to explanations and commentaries, often of significant length, and occasionally when different authorities physical cited.

Verschillende belangrijke werken in het Middelperzisch bevatten selecties uit de zand of Avestan texts, also of Avestan texts which have before been lost. Through comparison of selections from wandering texts and from remaining texts, it has been reachable to distinguish with the translations of Avestan works and the commentaries on them, and hence to some degree reconstruct the content of some of the purposeless texts. Among those texts is the Bundahishn, die heeft Zand-Agahih (“Kennis uit de Zand“) als ondertitel en is cruciaal voor de samenloop van de zoroastrische kosmogonie en eschatologie. Een andere tekst, de Wizdagiha, “Selections (from the Zand)”, by the 9th century priest Zadspram, is a key text for conformity Sassanid-era Zoroastrian orthodoxy. The Denkard, a 9th or 10th century text, includes extensive summaries and quotations of zand teksten.