What does Chapter 10 reveal about Sai Baba's unusual sleeping habits and the plank he used?

Chapter 10 provides a fascinating description of Sai Baba's sleeping arrangements. He would sleep on a narrow wooden plank, only about one span wide and four cubits long, which was suspended from the rafters like a swing using rags. Lamps would burn at his head and feet. The most mysterious aspect, as detailed in this chapter, was that his movements were imperceptible; no one ever saw him climb up onto this precarious plank or descend from it. This implied that the plank itself was merely for show, a testament to the Great Siddhis (powers) he possessed.