How does a Guru help a devotee see past the illusory nature of the world, as described by Sai Baba?

According to the teachings in Chapter 19, the Guru helps a devotee see past the world's illusions by grounding them in the eternal. Baba compares the transient world to "waves, bubbles, foam, whirlpools," which are all temporary forms of the same water, a display of Maya. He says that those with discrimination are not puzzled by this flux. The Guru, being one with the eternal Inner Self, provides this discrimination. By guiding the devotee to listen, reflect (Manan), and meditate (Nididhyasan) on truth, the Guru helps them to stop striving for the perishable and instead seek the "eternal gain," which is the unchanging, non-dual Self.