Based on Chapter 33, what was the specific role of Udi in the process of a devotee getting permission to leave Shirdi?

As detailed in Chapter 33, the giving of Udi played a crucial role when devotees sought permission to depart from Shirdi. The text states that when devotees were ready to return to their villages, they would ask for Baba's permission. It was a well-known practice that Baba would give them Udi upon their departure. The chapter clarifies that when Baba would say, "Take the Udi," this was understood to be the true granting of permission. This act of receiving the sacred ash from Baba's own hand would fill the departing devotee's mind with enthusiasm for their journey home, serving as both a blessing and a formal consent to leave.