The text says the Guru can 'strike a nail over the lines of destiny.' What does this mean, and what other spiritual benefits does one get from devotion to the Guru, according to Chapter 10?

The phrase 'strikes a nail over the lines of destiny,' as explained in Chapter 10, means that the Guru has the power to change a devotee's fate. By placing complete faith in the Guru's feet, one's predetermined destiny can be altered for the better. Beyond this, Chapter 10 describes numerous other spiritual benefits. The Guru's mere sight can break the 'knots of the heart' and eliminate attachments to worldly sense objects. Furthermore, devotion to the Sadguru destroys both accumulated (Sanchit) and current (Kriyaman) karmas, and he can place Knowledge (Samvitti) and the bliss of liberation (Moksha) directly into a devotee's hands, making the difficult spiritual journey effortless.