Chapter 10 mentions Baba's movements were 'imperceptible.' What specific example is given to illustrate this, and what is the spiritual explanation offered?

Chapter 10 illustrates Sai Baba's imperceptible nature primarily through the detailed account of his sleeping plank. This plank was four cubits long but only a span wide, tied to the rafters with rags. The text emphasizes that although Baba slept on it, no one ever knew when he climbed up or descended. The spiritual explanation offered is that this was possible due to the 'Great Siddhis (powers) residing within Him.' The chapter further speculates on his abilities by mentioning 'Anima' (the power to become minute), suggesting Baba’s movements were easy and unnoticeable because he could take the form of flies, insects, or ants.