Papyrus Jumilhac contains five more or less extensive versions of a myth according to which Anubis discovered the severed head of Osiris at Nedjit; the subsequent performance of an opening of the mouth enabled the head to reveal the places where the missing body parts are to be found. A corrected reading of essential phrases allows us to recognize the myth as an aetiology explaining the fabrication of Osirian clay figures during the festival of Khoiak. Furthermore, this new understanding sheds light on the local practices at Hardai which are not described in the famous Khoiak text at Dendera.