Praise be to Allah, the Lord of Creations, and Peace and blessings be upon our prophet Muhammad, the faithful and the honest.
 Oh, Allah, we know nothing but what You teach us. You are the All- Knower, the Wise. Oh Allah, teach us what is good for us, and benefit us from what You taught us, and increase our knowledge. Show us the righteous things as righteous and help us to do them, and show us the bad things as bad and help us to keep away from them.
  O Allah our Lord, lead us out from the depths of darkness and illusion, unto the lights of erudition and knowledge, and from the muddy shallows of lusts unto the heavens of Your Vicinity.
 Scientists hold that sleep is the greatest of all of Allah’s Divine Favors upon mankind. This is because it revives the human body and renews its energy. In this context, Allah, All-Mighty, says,

“And among His (Allah’s) Signs is your sleep by night; and by day, your seeking of His Bounty. Verily, in that are indeed Signs for a people who listen.”

[Aal Imran; 23]

 The  most recent studies in the field of sleep confirm that when man wakes  up and starts work, certain chemicals are produced in small amounts in his body. With time and labor, the amount of these chemicals increase until they reach a certain ratio in the blood. Therefore, messages are sent to the brain, which, in turn, sends neuro-electric orders to the sleep-centers in the nerve-endings. The nerve-endings either dissemble and cut off the neuro-electric current – which causes man to sleep – or assemble together, allowing the neuroelectric current to pass through – which keeps man awake. Hence, the mechanism of sleep is made up of a chemical substance, or a compound of substances, that are produced increasingly in the human body by time and labor, until messages are sent to the brain, which, in turn, sends neuro-electric orders to the sleep-centers in the nerve-endings, which dissemble, cutting off the neuro-electric current and causing man to feel exhausted and   fall asleep.
 Now, the question is: Whose arrangement is this?! Whose organization is this?! Whose creation is this?! How would our life be without sleep?! If man stays awake for two straight nights, he will certainly get confused and exhausted. So, what would happen to man if he were deprived of sleep?! Once again, we repeat Allah’s Divine Words,

“And among His (Allah’s) Signs is your sleep by night; and by day, your seeking of His Bounty. Verily, in that are indeed Signs for a people who listen.”

 In the human body there are centers for light sleep and centers for deep sleep. In other words, you might  lie in bed for eight hours. during which you are  sleeping deeply for two or three hours and are completely unconscious of anything around you. But during the rest of these eight hours, you are  sleeping lighty and conscious of all the things taking place around you: you are conscious of those who speak, come in, get out, or knock on the door.
 The question is: Who has put in the body centers for light sleep, others for deep sleep, and others for remaining awake?!
 A baby usually sleeps for long hours in order that its body grows. A five-year old child sleeps for 12 hours, an adolescent for 9 hours, and an adult for 7-8 hours.
 The question is: Who has planned sleep?! Who has set its periods and times?! Who has made it a time for rest and comfort for the muscles and organs of the body?! Once again, we reiterate Allah’s Words,

“And among His (Allah’s) Signs is your sleep by night; and by day, your seeking of His Bounty. Verily, in that are indeed Signs for a people who listen.”