The second issue

The scholars have differed over sleep and its effect on ablution, falling into three positions:

1. A group hold that sleep itself constitutes a state of minor ritual impurity; accordingly they oblige ablution for it, whether the sleep be brief or prolonged.

2. A second group maintain that sleep is not an impurity in itself. They therefore require ablution only when it is certain that a nullifier has occurred—according to those who set doubt aside—or when one is merely in doubt, according to those who give doubt legal weight. Some of the early Muslims even used to appoint someone to watch over them when they slept, that is, to determine whether any nullifier issued from them or not.

3. A third group distinguish between light, short sleep and deep, heavy sleep, obligating ablution for the latter but not for the former. This is the view adopted by the jurists of the major centers of learning and by the majority of scholars.

Because certain bodily postures are more conducive to deep sleep—and hence to the passing of wind—than others, the jurists have disagreed over the details.

• Mālik said: “Whoever sleeps lying down or in prostration must perform ablution, whether the sleep is long or short. One who sleeps sitting is not required to perform ablution unless he remains so for a long time.” As for one who sleeps standing, two reports are found in his school: in one he likens him to the one who bows, and in the other to the one who prostrates.

• Al-Shāfiʿī said: “Ablution is incumbent upon every sleeper, whatever posture he takes, except one who sleeps sitting.”

• Abū Ḥanīfah and his companions said: “No ablution is required except of one who sleeps lying down.”

The root of their disagreement lies in the seemingly conflicting prophetic reports on the matter. Some ḥadīths appear to indicate that sleep does not require ablution at all, such as the ḥadīth of Ibn ʿAbbās: “The Prophet—peace and blessings be upon him—entered upon Maymūnah and slept there until we heard his snore; then he prayed without performing ablution.” Likewise his statement—peace and blessings be upon him: “If any of you becomes drowsy while praying, let him lie down until the sleep leaves him, for he may wish to ask his Lord for forgiveness and end up cursing himself.” There is also the report: “The Companions of the Prophet—peace and blessings be upon him—used to sleep in the mosque until their heads nodded, then they would pray without renewing ablution.” All of these narrations are sound.

On the other hand, there are ḥadīths whose plain sense suggests that sleep itself occasions minor impurity. The clearest of them is the ḥadīth of Ṣafwān ibn ʿAssāl, who said: “We were travelling with the Messenger of Allah—peace and blessings be upon him—when he ordered us not to remove our leather socks on account of defecation, urine, or sleep, and not to remove them except because of major ritual impurity.” Thus he placed defecation, urine, and sleep on the same footing; al-Tirmidhī declared the report sound.

Among the supporting texts as well is the earlier ḥadīth of Abū Hurayrah, namely the Prophet’s words—peace and blessings be upon him: “When one of you wakes up from sleep, let him wash his hand before dipping it into the ablution water,” for its outward sense shows that sleep—whether little or much—makes ablution obligatory, and likewise the apparent sense of