How did Sai Baba sleep, and what was unusual about his sleeping arrangement as described in Chapter 10?

Chapter 10 provides a detailed and fascinating description of Sai Baba's unique sleeping habits. He would rest on a narrow wooden plank, merely four cubits long and one span (about nine inches) wide. This plank was not on the floor but was suspended from the rafters like a swing, tied at each end with old rags. Adding to the mystery, lamps would burn at His head and feet while He slept on this precarious bed. The chapter emphasizes that His movements—when He got onto the plank and when He got down—were completely imperceptible, with no one ever witnessing the act.