Investiture at the Navjote, and Wearing It Every Day After

A Zoroastrian child receives the sudreh together with the kusti cord at the Navjote, or Sedreh Pushi among Iranian Zoroastrians, an initiation performed once in a lifetime, usually between about seven and fifteen depending on community and family custom. A priest recites the prayers that invest the child with both garments in a single ceremony, after which the child is understood to have taken on personal religious responsibility, the Zoroastrian equivalent of a threshold into accountable adulthood in ritual terms, well before it is a threshold into civil adulthood.

From that day the sudreh is worn continuously, removed only for bathing and put back on at once, so that a Zoroastrian is, in traditional teaching, considered spiritually unprotected in the interval when it is off. Wearing it is inseparable from the kusti prayers recited over it several times a day, since the sudreh is the surface against which the cord is retied. Observance of continuous wear varies today, most visibly in diaspora communities where daily practice is harder to sustain unbroken, and Boyce's fieldwork among Zoroastrian communities documents that variation candidly rather than treating any one level of observance as the sole authentic form.