How does the analogy of the stone and the gem illustrate the Guru's expectations regarding faith and patience?

The analogy of the stone and the gem, presented in Chapter 19, offers a nuanced perspective on the Guru-disciple relationship. Both the stone and the gem undergo the same polishing process on a whetstone, just as different disciples receive the same guidance from a Guru. However, the outcome is vastly different: the gem becomes a brilliant jewel, while the stone merely becomes smooth. This illustrates that while the Guru's guidance is essential, the disciple's own inner qualities, including strong faith and patience, determine their ultimate spiritual transformation. The Guru expects a disciple to possess the wisdom and courage to truly absorb the teachings and shine, rather than just being superficially affected.