What's the meaning behind Sai Baba's story about the mother tortoise and her young?

The analogy of the mother tortoise, found in Chapter 19, is a profound teaching about the nature of a Guru's grace. Baba explains that his own Guru protected him with a "merciful glance," just as a mother tortoise on one riverbank nurtures her young on the other sandbank with her sight alone. This illustrates that a Guru's protection and spiritual nourishment are not dependent on physical proximity or verbal instruction, like a mantra. The loving gaze, or focused attention, of the Guru is sufficient to bring happiness and contentment to the disciple. Baba uses this to explain to a woman why he cannot give her a verbal 'upadesh' (instruction), telling her to simply "pay attention to me" for spiritual wealth to come to her.