There are numerous Muslim sleep traditions that Muslims try to follow in order to be in accordance with the practice of the Prophet (Peace be upon him) (Sunnah).

Early Bedtime and Early Wake Up Time

Muhammad (Peace be upon him) encouraged his companions not to be involved in any activity after Isha prayer (darkness prayer, which is around 1.5-2 hours after sunset). The Prophet (Peace be upon him) said, “One should not sleep before the night prayer, nor have discussions after it” [Reported by Sahih Al-Bukhari 574].
Additionally, Muslims are required to wake up for Fajr prayer, which is about one hour before sunrise. The Prophet did not sleep after Fajr prayer. In addition, the Prophet (Peace be upon him) told his companions that early morning work is blessed by Allah.
Perform Ablution (Wudoo) Before Going to Bed and Supplicate
It is reported in Sahih Muslim that one of the companions said that the Prophet (Peace be upon him) told him, “Whenever you go to bed, perform ablution like that for the prayer, and lie on your right side” [Reported by Sahih Muslim 2710]. And then he asked him to say the night prayers before sleep.

Dusting and cleaning the bed before sleeping
It has been reported that the Prophet (Peace be upon him) said, “When any one of you goes to bed, he should take hold of the hem of his lower garment and then should clean (his bed) with the help of that and then should recite the name of Allah” [Reported by Sahih Muslim 271].
Sleep Position

In Islamic culture, some sleep positions are encouraged while others are discouraged based on the practice (Sunnah) and recommendations of the Prophet Muhammad (Peace be upon him). Thus, many Muslims sleep on their right side, particularly, in the initial part of sleep. Muhammad (Peace be upon him) said, “Whenever you go to bed, perform ablution like that for the prayer, and lie on your right side” [Reported by Sahih Muslim 2710). In description of the sleep of the Prophet (Peace be upon him), a Hadith states, “When the Prophet (Peace be upon him) wants to go to sleep, he puts his right hand under his cheek” [Reported by Sahih Muslim 2713].

Modern scientific studies have suggested a beneficial effect of right lateral decubitus position on the heart. In particular, one study assessed the autonomic effect of three sleep positions (supine, left lateral decubitus, and right lateral decubitus) in healthy subjects using spectral heart rate variability analysis.[2] The results indicated that cardiac vagal activity was greatest when subjects were in the right lateral decubitus position. In addition, an animal study indicated that vagal stimulation has an antiarrhythmic effect.[3] Several studies have demonstrated that the recumbent position affects autonomic nervous system activity in patients with congestive heart failure, and that there is attenuation of the sympathetic tone when subjects are in the right lateral decubitus position. [[4]-[5]] Muslims tend to dislike sleeping in the prone position, and this is discouraged in the Islamic literature, even for infants. The Prophet (Peace be upon him) told a man who was lying on his stomach, “Allah and his Prophet dislike this position” [Reported by Sunan Al-Tirmdhi2768]. Modern medical studies have concluded that infants who sleep in the prone position have a seven-fold increased risk of sudden infant death syndrome (SIDS). This has led to “back to sleep” campaigns in Britain (1991) and in the United States (1994).

Turning Off Light before Sleep
It is narrated that the Prophet (Peace be upon him) said, “Put out lamps when you go to bed, shut the doors, and cover water and food containers” [Reported by Sahih Al-Bukhari 5301]. This may correspond with current scientific understanding that it is important to maintain a dark environment during sleep so as not to disrupt the circadian rhythm.

Yawning
Yawning is an unacceptable behavior for Muslims, especially in public places. If yawning occurs, the yawner is instructed to cover his mouth with his hand. The Prophet said, “Yawning is from Satan. If you are about to yawn, you should try to stop it as much as possible. If you yawn, Satan will laugh” [Reported by Sahih Al- Bukhari 3115].
Naps (Siestas)

Napping is a cross-cultural practice, and modern sleep scientists believe that napping provides benefits for all ages.A short mid-day nap (called Qailulah in Islamic culture) is a deeply embedded practice in the Muslim culture, and it takes a religious dimension (Sunnah) for some Muslims. The Prophet Muhammad (Peace be upon him) said, “Take a short nap, for Devils do not take naps” [Reported by Sahih Al-jamie, Al-albani 1647]. Another Hadith by Muhammad (Peace be upon him) provided details about the timing of the nap, “Sleeping early in the day betrays ignorance, in the middle of the day is right, and at the end of the day is stupid.” (Reported by Fath Al-Bari, p.73). A third Hadith reported in Sahih Al-Bukhari says, “We used to offer the Jumua (Friday) prayer with the Prophet and then take the afternoon nap” [Reported by Sahih Al-Bukhari 5923].

Friday is the weekend for Muslims, so napping on Friday may compensate for sleep debt that has accumulated during weekdays.

Previous research has shown that short daytime naps improve vigilance and cognitive functions, and are beneficial for memory consolidation.[8] In particular, a nap as short as 10 min can improve alertness and performance for 2.5-4 hours.[9] A recent study assessed the health effects of napping in 23,681 healthy Greek adults for an average of about six years. After controlling for potential confounders, the researchers concluded that those who napped at least three times weekly for about half an hour had 37% lower coronary mortality than those who did not nap.[10]

Al-Abid Zuhd E. The miracle verses and its impact about sleeping in Qur’an. Aljameah Alislamiah J 2010; 18:215-50.
Chen GY, Kuo CD. The effect of the lateral decubitus position on vagal tone. Anaesthesia 1997;52:653-7.

Vanoli E, De Ferrari GM, Stramba-Badiale M, Hull SS Jr, Foreman RD, Schwartz PJ. Vagal stimulation and prevention of sudden death in conscious dogs with a healed myocardial infarction. Circ Res 1991;68:1471-81.

Fujita M, Miyamoto S, Sekiguchi H, Eiho S, Sasayama S. Effects of posture on sympathetic nervous modulation in patients with chronic heart failure. Lancet 2000; 356:1822-3.

Kuo CD, Chen GY. Comparison of three recumbent positions on vagal and sympathetic modulation using spectral heart rate variability in patients with coronary artery disease. Am J Cardiol 1998; 81:392-6.

Gilbert R, Salanti G, Harden M, See S. Infant sleeping position and the sudden infant death syndrome: Systematic review of observational studies and historical review of recommendations from 1940 to 2002. Int J Epidemiol 2005;
Milner CE, Cote KA. Benefits of napping in healthy adults: Impact of nap length, time of day, age, and experience with napping. J Sleep Res 2009; 18:272-81.

Ficca G, Axelsson J, Mollicone DJ, Muto V, Vitiello MV. Naps, cognition and performance. Sleep Med Rev 2010; 14:249-58.

Ficca G, Axelsson J, Mollicone DJ, Muto V, Vitiello MV. Naps, cognition and performance. Sleep Med Rev 2010; 14:249-58.

Naska A, Oikonomou E, Trichopoulou A, Psaltopoulou T, Trichopoulos D. Siesta in healthy adults and coronary mortality in the general population. Arch Intern Med 2007; 167:296-301.