What happened when the two gentlemen from Goa came for Sai's darshan, specifically regarding the Dakshina?

As narrated in Chapter 36, when two gentlemen from Goa came for Sai Baba's darshan, a peculiar incident involving Dakshina (a monetary offering) occurred. Both men surrendered at Sai's feet, but Sai Baba acted with apparent partiality. He specifically asked for fifteen rupees from only one of the gentlemen, who gave it with joy. However, when the second man voluntarily tried to offer thirty-five rupees, Sai Baba immediately rejected his offering. This surprising act puzzled everyone present, including Madhavrao (Shama), prompting him to question Sai about the reason for his decision.