How does Chapter 16 contrast the gift of a Guru with that of a Chintamani, the wish-fulfilling gem?

Chapter 16 draws a significant comparison to highlight the unparalleled generosity of a Guru. A Chintamani, or wish-fulfilling gem, is limited in that it can only bestow what a person thinks of or desires. In contrast, the Guru's gift transcends the realm of ordinary thought and desire. The chapter wonderfully states that the Guru gives the "Unthinkable Object," which is identified as Brahman, to his devotee. This illustrates that the Sadguru provides the ultimate spiritual reality, a gift far beyond anything one could even conceive of asking for.