The four schools split over which kind of sleep breaks wudu

The verse of wudu lists the causes it knows and never mentions sleep. The parallel verse in Surat al-Nisa names intoxication, janabah, coming from the place of relieving oneself and contact with women, again with no mention of sleep. Because of that gap, scholars who held that sleep breaks wudu either went to the hadith or read the verse's opening as meaning rising from sleep, a reading reported from Zayd ibn Aslam in Malik's Mudawwana.Quran.com+2

Ibn Rushd notes that the verse's outward sense supports that reading for whoever accepts it. Al-Shafi'i's commentators in Mughni al-Muhtaj work through the same implied wording, noting that the verse's structure requires an omitted phrase such as from sleep. Ibn Rushd gives the opposite starting point: the chapter on nullifiers is built on the two verses' mention of the toilet and of touching women, together with the hadith that Allah does not accept the prayer of one who has broken wind until he performs wudu.Shamela+1

Ibn Rushd adds that Abu Hurayra's report about washing the hand on waking appears, on its face, to make sleep obligate wudu whether little or much. On the Companions' practice, Anas reports that they dozed while waiting for 'Isha and then prayed without renewing wudu, while Abu Hurayra is reported in the Mudawwana as saying that whoever is overcome by sleep must perform wudu.Sunnah.com+2

Anas said the Companions waited for 'Isha until their heads were lowered by dozing, then prayed without performing a new ablution (Sunan Abi Dawud 200), graded Sahih by al-Albani and Muhammad Muhyi al-Din Abd al-Hamid, and Sahih Muslim 376 by Zubair Ali Zai. Al-Buhuti cites it in Kashshaf al-Qina' as evidence that slight sleep by one sitting or standing does not break wudu.Sunnah.com+1

Ali reported the Prophet saying, The eye is the cord that ties the anus, so whoever sleeps should perform ablution (Sunan Ibn Majah 477), graded Hasan by al-Albani and Hasan by Muhammad Fouad Abd al-Baqi, but the sanad is called da'if by Shu'ayb al-Arna'ut and the hadith da'if by Zubair Ali Zai. The same report appears in Sunan Abi Dawud 203 with the same split in grading. A Mu'awiya version in Sunan al-Darimi reads, The two eyes are the binding strap of the anus. When the eye sleeps, the strap is loosened, with no grade attached in the source, and Abdullah ibn al-Mubarak's comment that one who sleeps standing owes no wudu is recorded right after it.Sunnah.com+2

Safwan ibn 'Assal said the Prophet commanded them on a journey not to remove their leather socks for three days except for janabah, but not because of defecation, urination, or sleep (Sunan an-Nasa'i 159), graded Hasan by Abu Ghuddah and al-Albani, with a hasan isnad by Zubair Ali Zai.Sunnah.com

Ibn 'Abbas spent the night at Maymunah's and reported that the Prophet slept until his snoring was heard, then got up and prayed without performing ablution (Musnad Ahmad 2194), graded sahih by Shu'ayb al-Arna'ut, with 'Ikrimah commenting that the Prophet was protected. A shorter version is sahih on the condition of the two shaykhs, and the same night is narrated in Sahih al-Bukhari 138, Sahih Muslim 763a, Sahih al-Bukhari 859, Sahih Muslim 763i and Sunan an-Nasa'i 1620. The reason given is the hadith, My eyes sleep, but my heart does not sleep, graded sahih on the condition of the two shaykhs.Sunnah.com+8

Ibn 'Abbas narrated that the Prophet prostrated, slept and breathed audibly, then prayed without wudu, saying, Ablution is only required of one who sleeps lying down, adding that when he lies down his joints relax (Sunan Abi Dawud 202). It is graded Da'if by al-Albani, by Muhammad Muhyi al-Din Abd al-Hamid, by Shu'ayb al-Arna'ut and by Zubair Ali Zai, and Abu Dawud himself calls the phrase a munkar report.Sunnah.com

When any of you wakes up from his sleep, he should not put his hand into the water for wudu until he has washed it, for none of you knows where his hand spent the night, graded sahih on the condition of the two shaykhs, and in the three-times version in Sahih Muslim 278a and elsewhere. If any of you becomes drowsy while praying, let him sleep until he knows what he is reciting (Sahih al-Bukhari 213).Sunnah.com+6

The Hanafi school holds that sleep breaks wudu when one is lying down, leaning back, or resting on something that would fall if removed, but not when sleeping standing, sitting, bowing or prostrating. Ibn Abidin reports the mu'tamad that sleeping in sujud, even inside the prayer, does not break wudu, though the Zahir al-Riwaya says it does, and that the sahih ruling for a sick man praying lying down who falls asleep is that his wudu breaks. Darul Iftaa Chicago quotes Multaqa al-Abhur and Sharh al-Wiqaya for the same limit, resting it on the lying down report.Shamela+2

The Maliki school holds that the criterion is the weight of the sleep, not the posture: heavy sleep breaks in any position, even briefly, while light sleep breaks when lying or prostrating but not when standing or sitting. Malik in the Mudawwana says that whoever sleeps in his prostration and the sleep becomes heavy and long, his wudu is broken; light sleep like a passing thought does not break it, and the same distinction applies to sleeping on a mount. Al-Dasuqi reports the mashhur as weighing the attribute of the sleep, while the Talkhis weighs both the sleep and the posture.Shamela+2

The Shafi'i school holds that sleep breaks wudu whenever the sleeper's buttocks are not firmly settled on the ground, however short the sleep; a firmly seated sleeper does not break wudu even if the sleep is long, and dozing never breaks it. Al-Nawawi defines sleep as relaxation of the body and loss of awareness, saying dozing and passing thoughts do not break wudu at all; if one buttock lifts before waking it breaks, if after or with the waking or in doubt it does not, and sleeping on the back with the buttocks on the ground does break. Mughni al-Muhtaj states that sleep is not a hadath in itself but a sign of passing wind, that the Prophet's sleep is one of his special traits, and that renewing wudu after sleep while firmly seated is recommended to leave the disagreement.Shamela+2

The Hanbali school holds that lying down breaks wudu little or much, while sitting breaks only if much, in one report; the apparent position from Ahmad is that standing and sitting are equal, with another narration that it breaks in every case. Ibn Qudama sets out the three categories and the reports from Ahmad, adding that if one doubts whether the sleep was long, wudu stands because purity is certain. Al-Buhuti exempts the Prophet and slight sleep by one sitting or standing.Shamela+2

The texts pull in two directions: whoever sleeps should perform ablution reads as a general rule, while the Companions dozing before 'Isha and praying without renewal shows that not every sleep counts. Ibn Rushd frames the whole disagreement as three positions, then explains the majority's solution: they carried the obligating reports to much sleep and the permissive ones to little sleep, and he notes that combining is preferable to preferring one side wherever combining is possible. He adds that al-Shafi'i instead restricted the exception to the posture of the sleeper, sitting only, because the Companions' sleeping while seated is authentically reported.Sunnah.com+3

The second reconciliation is causal. Al-Shafi'i's school and Ibn Qudama both treat sleep not as a hadath in itself but as a presumed cause of one, so the ruling follows the likelihood that wind passed. That is the reasoning Ibn Uthaymeen and the contemporary fatwas adopt, which is why doubt resolves in favour of the existing wudu.Shamela+5

The third is the Prophet's exemption. His sleep did not break his wudu because his heart stayed awake, and both the Shafi'i and Hanbali books list this among his special traits, which removes his reported prayer after sleeping from the general rule. The fourth is the grading dispute: the Hanafis rest their position on the lying down report, while Abu Dawud himself calls its key phrase munkar and four later graders call the hadith da'if.Shamela+8

IslamQA (fatwa 36889, 2005) holds that sleep breaks wudu when it is deep enough to remove awareness, citing Safwan's hadith, and reports that the majority combined the texts while the firmly seated view is the madhhab of the Hanafis and Shafi'is according to al-Majmu' 2/14. It says Ibn Taymiyya, Ibn Baz, Ibn Uthaymeen and the Permanent Committee chose the awareness criterion, quoting Ibn Uthaymeen that sleep itself is not a nullifier since slight sleep does not break wudu. A later IslamQA answer (111837) adds that a doubt about whether the sleep was deep leaves the wudu intact, quoting Ibn Taymiyya that purity is established by certainty and is not removed by doubt.IslamQA+1

Egypt's Dar al-Ifta rules that wudu and prayer are nullified by deep sleep that reaches the heart and leaves no awareness, because it is a presumed cause of passing wind, while the drowsiness in which a person still hears those around him nullifies neither. It cites al-Kasani's Bada'i' that sleeping lying down breaks wudu whether inside or outside the prayer, and Ibn Abd al-Barr's Istidhkar that dozing does not break the prayer and therefore does not break wudu. Dar al-Ifta also notes the separate recommendation of performing wudu before sleeping, as does IslamQA.Dar al-Ifta (Egypt)+2

IslamOnline presents the same reconciliation, quoting Sayyid Sabiq's Fiqh al-Sunna, and lists al-Nawawi's eight positions on the question.IslamOnline Fiqh+2