Allah Ta’aalaa says: "Stand up during the night, but a portion (of the night); half the night or less than half the night." [Qur'aan]
The aforementioned Aayah commands standing up during the night so that the Nafs becomes accustomed to striving. In this way the ability of the Nafs (to submit to righteousness) attains strength and perfection. Standing up during the night is most efficacious for bringing the Nafs into submission. All forms of Ibaadah, be it Du’a or Qir’at, Salaah or Zikr and be it external (Zaahir) or internal (Baatin), are fulfilled in the proper manner during the night. The meaning of proper external (Zaahir) discharge of Ibaadah during the night is the proper and correct recital of the words since the time available is ample. The meaning of proper internal (Baatin) discharge of Ibaadah is that during the night one derives greater pleasure in Ibaadah. This is in fact what is meant by the tongue and the heart conforming.
During the month of Ramadhaan the Shariah has ordered the performance of Taraaweeh Salaah during the night because it envisages Taqleel-Manaam. Like Sawm (fasting) has its role in Taqleel-Ta’aam, Taraaweeh has its role in Taqleel-Manaam. Like the change of habit (i.e. in eating times) during fasting induces Mujaahidah, so too, does the change of habit in Taraaweeh. The general habit prevailing is to sleep after Ishaa. The command of Taraaweeh brings about a change in the habit of sleeping, and this changing of habit is difficult on the Nafs. This is precisely Mujaahidah.
In Taqleel-Manaam the Shariah does not stop at mere awakefulness, but instructs the observance of Ibaadah during the time of awakefulness. Allah Ta'ala praises pious servants in the Qur'aan: "In the fatter part of the night they make Istighfaar."
Elsewhere in the Qur'aan it is said: "They separate their sides from the beds calling their Rabb in fear and hope..."
In other words, they perform Salaah during the night. However the trend of the Aayah comprehends all forms of Ibaadah, hence it applies to Du’a and Zikr as well. Furthermore, beside the Deeni benefits in sleeping less, the physical health also benefits. Less sleep creates Noor (celestial light) on the face. The following is the statement of a Muhaddith in this regard:
"The face of one who performs Salaah in abundance during the night becomes beautiful during the day."
Excessive sleep is detrimental to the physical health as well. It reduces or stunts the capacity of contemplation in a person. This in turn brings . about harm in both Deeni and worldly activities. A person who is given to excessive sleeping is never able to be punctual in time.
Moderation in Qillat-Manaam
Moderation in this Mujaahidah is also desirable. Nowadays this moderation means sleeping at least six or seven hours, If sleep becomes over-bearing then one should not ward it off. In this case postpone your Wazeefah (act of lbaadah) and sleep. The Wazeefah should be completed later. If the sleep is not over-powering then one should adopt courage and remain awake. If sleep is warded off when it is really over-powering then the consequence will be harmful to the mind as well as to the body in general. Confused thoughts will arise in the mind and at times one is deceived into believing such confused thoughts to be inspiration (Ilhaam). Such a person then considers himself to be a saint. The final result is insanity. Hence, the explanation of the Hadeeth of Rasulullah Sallallahu Alayhi Wasallam:
"When any of you rises in the night and finds that he is unable to recite the Qur’aan properly (due to feeling sleepy), and he does not know what he is reciting, then he should lay down."
The advice in such cases of sleepiness is to lay down and not to ward off the sleep. Some people who are extreme in their observance of Taqleel-Manaam and other aspects of Mujaahidah and do not heed the possibility of harm, should take advice from this Hadith. This Hadith is an admonishment for them. The advice given in this Hadith is two-fold.
1. At times extremism in Mujaahidah proves detrimental to the physique.
2. When the words are not recited correctly because of over-powering sleep then the necessary Thawaab will not be obtained. Thus remaining awake will serve no beneficial purpose in this case.