For devotees of Sai Baba there is an emotional attachment to udi as a tangible form of Baba’s blessings, a vehicle for Baba’s grace and a link to Baba himself. People usually put it on the forehead and/or in the mouth. Sri Babuji also gives Baba’s udi as a symbol of Baba’s blessing.
When a Westerner unfamiliar with the custom once asked him why he did this, Sri Babuji replied that because the udi is from the fire that was lit and touched by Baba, the ashes are a connection to Baba and to his touch – and thus no ordinary ash. Putting the udi on the forehead, says Sri Babuji, “always gives me the experience of the touch of my Beloved and the udi is a symbol of his grace.