What happened when two gentlemen from Goa visited Sai Baba, specifically in relation to their offerings?

According to the account in Chapter 36 of the Shri Sai Satcharitra, two gentlemen from Goa came for Sai Baba's darshan. A peculiar event transpired regarding their monetary offerings, or Dakshina. Sai specifically requested fifteen rupees from one of the men, which he gave with joy. However, when the second man attempted to offer thirty-five rupees of his own accord, Sai Baba immediately rejected it. This display of apparent partiality was so surprising that it caused everyone present, including Madhavrao (Shama), to wonder about the reason behind Baba's actions.