(18:18) And did not say; "You would have thought them dead,...

(18:18) And did not say; "You would have thought them dead, as they lay sleeping," as the sign of awakening is 'eye wink'. Allah preserved their eyes from blindness through blinking, as the eye if kept closed for a long period of time will be blind, because the optic nerve will shrink and die, and if it is kept open, the cornea will be affected with corneo-xerosis, and blindness.

So, coolness in this gap in the Cave away from the heat of the sun that did not touch them, was sufficient to inhibit bodily metabolism for the preservation of their bodies all this long period. Had they been only asleep, they would have needed water and food to survive, and would have been awaken by the need to urinate after some hours. But Allah inhibited all their biological functions and preserved their bodies in a living shape.

So, He said: "You Therefore, this rare status of theirs would have aroused terror, if seen, as they were not alive or dead.

They were asleep, yet their eyes were blinking: "Had you observed them surely you would have turned your back on them in flight, and been filled with terror of them." (18:18) As Allah preserved their eyes through blinking, He also preserved their bodies from ulcers through constant turning: "While We turned them now to the right, now to the left" (18:18)w So that they would not be affected with pressure sores. Previous…