The rite is known almost entirely from twentieth century ethnography. Anzar appears in Amazigh oral tradition, but no documentary record has been identified between antiquity and the modern recording, so claims that the procession is a pre-Islamic survival rest on nothing that can be checked, and no dated alternative account exists.
What would resolve this An attestation of the procession, or of a recognisably related rite, in medieval or early modern Maghribi Arabic writing, in an Amazigh manuscript tradition, or in a travel account with a firm date.
OpenAmazigh philology and the ethnohistory of the Maghreb, with medieval Arabic textual scholarshipMircea Eliade (ed.); Lindsay Jones (ed., 2nd ed.), Encyclopedia of Religion