How does the analogy of the gem and the stone from Chapter 19 relate to the teachings on Faith and Patience?

The analogy of the gem and the stone in Chapter 19 serves as a powerful illustration of the importance of Faith and Patience. The chapter explains that even if a powerful Guru provides guidance—symbolized by the whetstone—the disciple's own inherent quality determines the outcome. Both a stone and a gem are rubbed on the whetstone, but 'a gem becomes a sparkling diamond, while a stone remains smooth.' This relates directly to the teaching that a Guru expects 'strong faith at the Guru’s feet and the strength of courage which is patience.' A disciple possessing these virtues (the gem) can be polished into brilliance, whereas a disciple without them (the stone) will not achieve the same spiritual luster, even under the same guidance.