In Chapter 19, Shri Sai wanted to receive a secret 'ear-mantra' from his Guru. What was this mantra, and why did his Guru refuse to give it to him?

According to the account in Chapter 19, Shri Sai did have a strong desire to receive a secret instruction, or 'ear-mantra,' from his Guru after serving him tirelessly. However, the text explicitly states that despite his efforts, his Guru 'wouldn't give me a 'ear-mantra'.' The provided passages do not reveal what the specific mantra was, nor do they explain the Guru's exact reasons for withholding it. Instead, the narrative shifts to what the Guru did ask for, which were the two 'paise' of Faith and Patience. The focus of the teaching in Chapter 19 is on these virtues rather than on the secret mantra itself.