What are the primary obstacles that obscure self-luminous knowledge, and what analogies are used to describe this process?

According to the wisdom in Chapter 50, even though knowledge is self-luminous, it can be hidden and obscured by powerful internal forces. The primary obstacles identified are lust, anger, and the overarching power of Maya, or ignorance. Several potent analogies are used to illustrate this covering effect. Just as a clean mirror can be covered by a layer of dust, or the bright light of a fire can be obscured by smoke, so too is knowledge hidden by these negative qualities. Another powerful image used is that of Rahu eclipsing the moon's orb or thick moss completely covering the surface of clear water, showing how Maya can completely cover one's true nature.