You would have supposed them to be awake, whereas in fact they were asleep. We moved them to the right and to the left, and, at the entrance, their dog stretched out its paws. If you had looked down and seen them, you would have turned from them and run, and have been filled with terror at the sight of them. (Quran chapter 18 verse 18)
This passage discusses the importance of movement in sleep, and how it affects a person's health. It makes reference to the Companions of the Cave, who remained asleep for hundreds of years without encountering any health issues. It also explains how, when people remain in the same position for a long time, they can suffer from circulation difficulties, sores, and blood clotting. These sores, known as "bed sores" or "pressure sores," are caused by the pressure on one part of the body not moving for a long period of time.
The sores can become serious and even lead to death if not treated, but they can be avoided by changing the position of the body every 15 minutes. This idea was only discovered in the last century, yet it is referred to in the Qur'an, making it a miracle. Thus, the importance of movement in sleep and its effect on sores, blood, and pressure is highlighted.
Notes:
177. Ibid.
178. Treating Pressure Sores (Agency for Health Care Policy and Research: 1994).
179. Kenneth Davis, Jr., "The Acute Effects of Body Position Strategies and Respiratory Therapy in Paralyzed Patients with Acute Lung Injury," Critical Care 5 (2001): 81-87;
www.biomedcentral.com/1364-8535/5/81/abstract