Why did Sai Baba ask Madhavrao to collect exactly fifteen rupees in Dakshina for the construction of a new hospital in Shirdi?

The source text does not state that the Dakshina was for a new hospital. While Chapter 18 does mention an incident involving fifteen rupees, the details are different. Baba sent a message instructing Shama (Madhavrao Deshpande) to give fifteen rupees as Dakshina. There is no mention of Madhavrao collecting money, nor is there any purpose specified for the Dakshina, such as hospital construction. The chapter presents this as an example of Baba's mysterious play and his interactions with his close devotees.