What was the surprising message about Dakshina that Madhavrao brought to Shama from Baba?

A curious interaction is described in Chapter 18 involving a message from Sai Baba delivered by Madhavrao. Madhavrao approached Shama (the narrator) stating he had a message from Baba: to collect fifteen rupees as Dakshina from him. Shama was utterly surprised by this request. Instead of giving the money, he cheekily responded that Madhavrao should tell Baba his "namaskar" (respectful greeting) was his form of Dakshina. Madhavrao, in good humor, accepted this, remarking that fifteen namaskars had been received, and then urged Shama to come and talk as Baba had also instructed.