Sleep

Imam Bukhari and Muslim narrated from 'A'ishah that the Prophet said: "If one of you to feel sleepy, you should lose sleep until mengantuknya. If a person prays when sleepy likely he read forgiveness when in fact he is disparaging himself."

In a hadith mentioned the story of Abu Darda ', which, inter alia, did not want to sleep at night because they want to do worship. Salman, his friend, had greeted him by saying: "Lord no right to you, your body has rights upon you and your wife is right on you. Give to all this right." When the Prophet heard the word Salman, he said: "It is true that Salman." (Bukhari)

In another Hadith narrated that the Prophet entered the mosque and saw the rope that spans two columns. After asking, he was told that the belt belonged to Zainab that he can hold on to him when tired to pray. Prophet continued to issue directions:
"Open this rope shall make one of you to stand when he's fit, and when we're sleepy hendaklah sleep." (Bukhari, Muslim)

All this shows that Islam is very concerned about productivity within each practice. It also showed the correlation between productivity and quality with the fitness of a person.

Daytime sleep was considered to be one sign of laziness. Muslims consider it a virtue as long as someone is not excessive with it.

In the book 'Misykatul Masabih' said of one of the sunnah practices that performed by the Prophet: "Sleep a little in the afternoon (qailulah) is not shameful. He is doing it."

Imam Al Ghazali in the book 'Ihya Ulumuddin' has said: "Let the person does not leave sleep during the day because it helps worship in the evening as the morning to help fast during the day. It is preferable is the sun to rise before Zuhr."

Wallahua'lam.