(17–18) “You would see the sun, when it rose, incline away from their cave toward the right, and when it set, pass them by toward the left, while they lay in a spacious part of it. That was one of Allah’s signs. Whoever Allah guides is truly guided; but whoever He leads astray, you will never find for him a guiding protector. * You would think them awake, though they were asleep. We turned them to the right and to the left, while their dog lay with its forelegs outstretched at the entrance. Had you come upon them, you would have turned and fled from them and been filled with terror at the sight of them.”

That is, Allah protected them from the sun. He provided them with a cave positioned so that, when the sun rose, it inclined away from it toward the right, and when it set, it inclined away from it toward the left. Thus, its heat did not reach them and cause their bodies to decay. “While they lay in a spacious part of it”—that is, in a spacious part of the cave—so that air and breezes could reach them, dispelling the staleness and discomfort of the confined space, especially during their prolonged stay. This was one of Allah’s signs, demonstrating His power, His mercy toward them, His response to their supplication, and His guidance of them even in these matters. Hence He said: “Whoever Allah guides is truly guided.” That is, guidance can be attained only from Allah, for He is the One who guides and directs people to what benefits them in this world and the Hereafter. “But whoever He leads astray, you will never find for him a guiding protector.” That is, you will find no one to take him into his care and manage his affairs in a manner conducive to his well-being, nor anyone to guide him to goodness and success, for Allah has decreed misguidance for him, and none can overturn His decree.

“You would think them awake, though they were asleep.” That is, you, the observer, would think [that they were] (1) awake, although they were sleeping. The commentators said that this was because their eyes remained open so that they would not be damaged. Anyone looking at them would therefore think they were awake, though they were asleep. “We turned them to the right and to the left.” This, too, was part of His preservation of their bodies, for the earth naturally consumes bodies that remain in contact with it. It was therefore part of Allah’s decree that He turn them from side to side, right and left, sufficiently to prevent the earth from causing their bodies to decay. Allah Most High was able to protect them from the earth without turning them, but He is Wise: He willed that His established way in creation should run its course and that causes should be linked to their effects.