The Posture of Sleep That Breaks Wuḍūʾ

The disagreement

• The four Imams agreed that heavy deep sleep necessitates ablution (wudu), and that light sleep is not a ritual impurity (hadath). They also agreed that sleeping while lying down nullifies ablution, and sleeping while sitting does not nullify ablution.
• They disagreed regarding the other postures of sleep that nullify ablution, and the disagreement consists of four opinions.

The opinions

• Sleep is nullifying if it is while lying down, whether it is long or short:
• Held by: Mālik.
• The nullifying sleep is sleep in any posture except sitting
• Held by: al-Shāfiʿī.
• There is no ablution except for one who sleeps while lying down
• Held by: Abū Ḥanīfah.
• Nullifying sleep is in any posture except light sleep while sitting or standing:
• Held by: Aḥmad.

Evidence

First opinion

• General Rule on Postures: The sleep that is—mostly—a cause for ritual impurity is that which contains: heaviness, length or a loose posture. Thus, length and heaviness in any posture are mostly the cause for ritual impurity.

Second opinion

• Evidence for the Sitting Exception: What is established: "That the Companions of the Prophet ﷺ used to sleep in the mosque until their heads would droop, then they would pray and not perform ablution." [[Reported by: Muslim]. This indicates the exception of the sitting posture from the sleep postures.

Third opinion

• The Hadith of Ibn ʿAbbās رضي الله عنهما: He ﷺ said:

«لَا وُضُوءَ عَلَى مَنْ نَامَ قَائِمًا أَوْ قَاعِدًا أَوْ رَاكِعًا أَوْ سَاجِدًا، إِنَّمَا الوُضُوءُ عَلَى مَنْ نَامَ مُضْطَجِعًا، فَإِنَّهُ إِذَا نَامَ مُضْطَجِعًا اسْتَرْخَتْ مَفَاصِلُهُ»

"There is no ablution required for one who sleeps standing, sitting, bowing, or prostrating; ablution is only required for one who sleeps lying down, for when he sleeps lying down, his joints relax." [[Reported by: Ahmad, Abū Dāwūd, al-Tirmidhī; and more than one scholar weakened it].

• The Statement of ʿUmar ﷺ: He said: "When one of you sleeps lying down, let him perform ablution." [[Reported by: al-Muwaṭṭaal-Bayhaqī].

Forth Opinion

• Historical Practice: What is established is that the Companions of the Prophet ﷺ used to sleep in the mosque sitting, and they would not perform ablution, and they would pray [[Reported by: Muslim].

The Preponderant View

• Light sleep in any posture does not nullify ablution as long as the person remains aware of his surroundings; because sleep is not a ritual impurity in itself, but rather a presumption of ritual impurity. And Allah knows best.

References

Bidāyat al-Mujtahid wa Nihāyat al-Muqtaṣid (1/71), Badā’iʿ al-Ṣanā’iʿ (1/250), Tabyin al-Haqa'iq (1/52), al-Sharḥ al-Ṣaghīr (1/141), al-Fawākih al-Dawānī (1/178), Nihāyat al-Maṭlab (1/124), al-Bayān (1/175), al-Sharḥ al-Kabīr (2/21), al-Mughnī (1/235), Sharḥ Ibn Zāḥim (1/217).