Could you explain the analogy of the mother tortoise that Sai Baba used to describe his Guru's care?

Certainly. In Chapter 19, Sai Baba uses the analogy of a mother tortoise to illustrate the silent, powerful way his Guru cared for him. He explains that the mother tortoise can be on one side of a river while her young are on the other sandbank. Without any physical contact or verbal communication, she nurtures them and brings them contentment simply through her loving gaze. Baba stated, "Just as a mother tortoise feeds her young with her sight alone, such was the way of my Guru; he protected his child with his gaze." This powerful metaphor emphasizes that the Guru's grace and protection are transmitted through a loving, merciful glance, a force more potent than any formal instruction or mantra.