PRESENCE OF SENSORY NERVES IN THE SKIN
Modern scientific research has shown that pain and heat sensitive nerve endings are widespread in the superficial layers of the skin, but most of the deep tissues are only weakly supplied (Medical Physiology, A.C. Guyton, p.593). It is also known that if the skin is burnt completely then these nerve endings can be destroyed.
Over 1400 years ago the Quran provided an insight into pain physiology, by indicating that if the skin is burnt through then its' sensitivity to pain is reduced.
"As for those who reject Our signs, We shall expose them to the Fire. Every time their skins are burned off, We will replace them with new skins so that they may taste the torment. Allah is Almighty, All-Wise." (The Quran - Al-Nisa 4:56)
The above verse indicates a clear relationship between feeling pain and having an intact skin. Intense burns causes the skin and nerve endings to be destroyed, so replacing the skin by new skin maintains the intensity of the punishment. Science has only recently discovered that the skin contains most of the pain sensitive nerve endings. This level of knowledge regarding skin physiology was simply not known at the time the Quran was revealed over 1400 years ago. Modern scientific knowledge therefore, allows us to understand certain verses of the Quran which until now, it has been impossible to fully interpret.