Based on Chapter 30, what is the transformative power of Sai's grace and how does it specifically affect a devotee's mind and knowledge?

According to the teachings presented in Chapter 30, Sai's grace possesses a profound, transformative power. The text explicitly states that upon whomever Sai bestows His grace, that individual attains 'inconceivable great power.' This is not merely material power, but the spiritual wealth of discrimination between the Self and non-Self, which encompasses all true knowledge. Furthermore, when a devotee is caught in worldly difficulties and their mind is troubled, simply remembering Sai Nath brings peace. The chapter positions Him as the sole giver of peace to an anxious mind, demonstrating that His grace provides both supreme knowledge and mental tranquility.