Husparam nask
The Husparam nask is the seventeenth nask of the Sasanian Avesta. The work itself is lost, but its content can be reconstructed from references in Book 8 of the Denkard and the Rivayats. The Nerangestan and Herbedestan are considered to have originally been part of this nask.The Sasanian Avesta was organized into 21 nasks, i.e., volumes, which were grouped into 3 divisions; the Gāhānīg, Hada Mānsrīg, and Dādīg. Within this scheme, the Husparam nask was part of the legal nasks and it content, consequently convered a wide range of legal topics. It consisted of either 30 or 60 fragards depending on the source. Edward William West estimates, that the Husparam nask consisted of ca. 44.900 words of Avestan text accompanied by ca. 403.600 words of commentary in Pahlavi, making it the third longest nask overall.In the extant Avesta
Two texts in the extant Avesta are considered to have been part of the Husparam nask, namely the Nerangestan and Herbedestan. The Herbedestan is mainly a text concerned with the education of Zoroastrian priests, namely the Herbeds. The Nirangestan follows the Herbedestan in the extant text and covers matters of the ritual. Together with the Vendidad, these two texts comprise the only surviving parts of the legal nasks and represent the remnants of the Zoroastrian learned tradition, compared to the liturgical tradition that forms the rest of the extant Avesta.