What does Sai Baba identify as the two most essential qualities for a disciple to offer their Guru?

According to the teachings in Chapter 19, Sai Baba emphasizes that the two most important offerings a disciple can make are not material but spiritual. He refers to them metaphorically as "two paise," which he clarifies are Faith (Nishtha) and Patience (Saburi). He explains that his own Guru was one whose desires were fulfilled and had no need for worldly money. When Baba gave his Guru these two qualities, his "Guru-Mother was pleased." Furthermore, the text describes Faith and Patience as being like two sisters, dear as life to each other, highlighting their interconnected and fundamental importance on the spiritual path.