The great liturgies of Zoroastrianism, the Yasna with its haoma ceremony, the Visperad, the Vendidad service, belong to trained priests in consecrated precincts. The Khordeh Avesta exists so that the rest of the community can pray, and its selection maps the devotional day of an observant Zoroastrian. The kusti prayers accompany the untying and retying of the sacred cord over the sedreh shirt, performed on waking, after ablutions and before prayer, the small rite that frames a Zoroastrian's whole day from initiation onward.
The five Gahs assign a short prayer to each watch of the day, dawn to midnight, each with its presiding spirits. The five Niyayesh litanies serve the recurring objects of reverence, the sun saluted three times daily, Mithra of the wide pastures, the moon, the waters and fire, the son of Ahura Mazda, honoured whenever one stands before a flame.
Around these cores gather the Afrinagan blessings recited at festivals and memorial days, the Sirozah formulas honouring the divinity of each of the thirty days of the month, and a selection of the Yashts, commonly including those to Ohrmazd, Ardwisur Anahid, Srosh, Mihr, Warharan and Ashtad, hymns whose full corpus belongs to the wider Avesta but whose favourites travel in the prayer book. The whole is portable religion, and the book's domestic ubiquity has made it, in practice, the scripture most Zoroastrians hold and use.