How does Chapter 10 articulate the power of the Guru in relation to a devotee's karma and destiny?

Chapter 10 presents a profound view on the power of the Guru, identifying him as the "one eternal God" in contrast to other illusory gods. It asserts that a Sadguru like Sai Baba has the ultimate authority over a devotee's fate, capable of changing it completely, a concept powerfully conveyed by the phrase that He "strikes a nail over the lines of destiny." As detailed in this chapter, the Guru's grace directly impacts a devotee's karmic account. By his mere sight, the "knots of the heart are broken," and more significantly, both accumulated (Sanchit) and current (Kriyaman) karmas are destroyed. This demonstrates that sincere service and faith in the Guru can transcend the binding laws of karma.