What exactly happened to Kaka Mahajani's skeptical friend that made him bow down to Sai Baba?

Kaka Mahajani's friend, who had firmly resolved not to bow, experienced a profound change of heart upon meeting Sai Baba. The narrative in Chapter 35 explains that as the friend set foot on the step of the mosque, Baba saw him from a distance and called out in sweet words, "Why have you come in this manner?" The friend was immediately astonished because the tone and vocal style were a perfect imitation of his own deceased father's voice. The text notes that hearing such speech, as if from his father's mouth, caused the friend to melt inside, completely forgetting his previous resolve and spontaneously bowing his head at Baba's feet.