What analogies did Sai Baba use to explain how Ignorance covers Knowledge?

In Chapter 39, Sai Baba provided several vivid analogies to illustrate his point that Knowledge is ever-present but veiled by Ignorance. He explained that just as a membrane covers a fetus, dust covers a mirror, or ash covers a fire, so too does Ignorance cover Knowledge. He further elaborated with the example of moss covering pure water; a wise person must remove the moss to access the water that is already there. Another powerful image he used was that of a solar or lunar eclipse, where celestial bodies obstruct our vision of the sun or moon, which are themselves always shining. Finally, he compared Ignorance to a film growing over an eye, which obscures the natural power of seeing.