Avesta other general. The following categorization is as described by Jean Kellens (see bibliography, below). The "Yasna" (from "yazišn" "worship, oblations", cognate with Sanskrit "yajña"), is the primary liturgical collection, named after the ceremony at which it is recited. It consists of 72 sections called the "Ha-iti" or "Ha". The 72 threads of lamb's wool in the "Kushti", the sacred thread worn by Zoroastrians, represent these sections. The central portion of the Yasna is the "Gathas", the oldest and most sacred portion of the Avesta, believed to have been composed by Zarathushtra (Zoroaster) himself. The "Gathas" are structurally interrupted by the
Avesta year, the third is recited at the six seasonal feasts, and the fourth at the beginning and end of summer. All material in the "Avesta" that is not already present in one of the other categories falls into a "fragments" category, which – as the name suggests – includes incomplete texts. There are altogether more than 20 fragment collections, many of which have no name (and are then named after their owner/collator) or only a Middle Persian name. The more important of the fragment collections are the "Nirangistan" fragments (18 of which constitute the "Ehrbadistan"); the "Pursishniha" "questions," also known