What was the message Baba sent to Shama about Dakshina, and how did Shama respond?

In a notable event from Chapter 18, Sai Baba sent a message to Madhavrao Deshpande, also known as Shama. A devotee serving Baba in the Masjid was suddenly told to go to Shama's house and collect fifteen rupees as Dakshina. The instruction was also to sit and talk with Shama for a while before returning. When Madhavrao heard the message, he was very surprised. Instead of providing the money, he offered a devotional and clever response. He told the messenger to convey his 'namaskar' (a respectful bow) to Baba, declaring, "this is our Dakshina." The messenger accepted this, acknowledging that fifteen namaskars had been received in place of fifteen rupees.