Unpack the meaning of the analogy involving the stone and the gem found in Chapter 19. How does it relate to the development of a disciple?

The analogy of the stone and the gem, detailed in Chapter 19, serves to illustrate how a Guru's teachings can have different effects depending on the disciple's inherent nature and readiness. The text explains that both a stone and a gem are polished by the same process on a whetstone. However, 'the stone remains a stone, but the gem becomes a brilliant jewel.' This metaphor suggests that while the spiritual guidance from a Guru is constant, the disciple's receptivity and inner quality determine the outcome. A disciple who is like a 'gem' will become a 'sparkling diamond,' achieving true brilliance. In contrast, another disciple, like a 'stone,' might be smoothed but will not gain the same luster, emphasizing that a Guru expects 'the disciple's wisdom' to complement the teaching.