Based on the provided texts, how does a pure heart relate to Self-realization, and what role does greed play in corrupting this process?

The texts establish a direct link between a pure heart and Self-realization, with greed acting as the primary corrupting agent. Chapter 17 explains that the Earthly world is desirable for seekers precisely because it is where "purity of heart occurs, and the intellect becomes clear like a mirror," which allows the pure nature of the Self to be reflected. Conversely, greed is described as having an "eternal enmity with Brahman." It fosters a dissatisfied and distracted mind, leading one to engage in conduct prohibited by sacred texts. According to Chapter 17, if even one greed remains in the heart, all spiritual practices are rendered useless. Therefore, destroying greed to attain a pure heart is a critical prerequisite for a Guru's teachings to be effective and for one to truly realize the Self.