Can you explain the concept of the Guru being the 'true Brahman' and how that relates to spiritual practice?

In Chapter 45, the text presents a profound philosophical concept for spiritual practice. It establishes a core duality: Brahman is eternal, while the world is transient. The crucial step is the identification of the Guru as the true Brahman, a solid mass of Brahman-consciousness. The recommended spiritual practice, therefore, is to renounce the transient world, which gives rise to dispassion (Vairagya), and to meditate exclusively on the Guru. This constancy of feeling and singular focus on the Guru, who is the embodiment of the eternal Brahman, is presented as the very means to achieve the spiritual goal. This eventually leads to seeing divinity in all beings, a state called 'undifferentiated worship' (Abheda-bhajan).