Can you tell me about the incident with the two gentlemen from Goa who visited Sai Baba?

Chapter 36 of the Shri Sai Satcharitra recounts the story of two gentlemen from Goa who came together for Sai Baba's darshan. Upon their arrival, a curious event unfolded. Sai asked for a dakshina of fifteen rupees from only one of them, which the man gave with joy. However, when the second gentleman offered thirty-five rupees of his own accord, Sai Baba immediately rejected the offering. As mentioned in Chapter 36, this seemingly partial act surprised everyone present, including Madhavrao (Shama), who then questioned Sai about the differing treatment of the two visitors.