How does Sai Baba use analogies to explain the relationship between knowledge and ignorance?

In Chapter 39, Sai Baba masterfully employs several analogies to clarify how Ignorance obscures inherent Knowledge. He compares Ignorance to a membrane covering a fetus, dust on a mirror, or ash covering a fire. In each case, the underlying reality—the fetus, the mirror's reflection, the fire's heat—is always present but concealed. He also likens Ignorance to a film or cataract growing over the eye, which obstructs its natural power of seeing, which is Knowledge itself. Another powerful image he uses is that of an eclipse, where Rahu and Ketu temporarily block our view of the ever-shining sun and moon. These examples all reinforce his central point that Knowledge is not created or taught, but simply revealed once the obstruction of Ignorance is skillfully removed.