2 – We have linked the ruling to night-sleep because of the Prophet’s words, “for he does not know where his hand spent the night.” The term baytūtah (بيتوتة) refers specifically to sleeping at night. We shall later cite the majority view that the hands are to be washed after any sleep, whether at night or during the day.

3 – The ḥadith forbids immersing both hands in the vessel before washing them three times. If, however, one hand has been washed while the other has not, it is permissible to dip the washed hand alone, for each hand carries its own ruling. Mentioning the “vessel” shows that the prohibition concerns utensils only and does not extend to pools, ponds, or cisterns.

4 – Some of our scholars inferred from this report that once the hand of a person who has risen from night-sleep is dipped into water, that water forfeits its purifying capacity and becomes ritually clean yet no longer purifying. This opinion is weak. The sound view is that the water retains its purifying nature, for water is not rendered impure unless one of its qualities is actually altered by impurity.

5 – Al-Khaṭṭābī said: The ḥadith indicates that exercising caution in acts of worship is preferable. Al-Nawawī added: provided that such caution does not cross the boundary into obsessive misgiving.

6 – The report recommends using discreet language for matters that people find embarrassing, so long as the intended meaning is conveyed.

7 – Anyone who hears a sunnah of the Messenger of Allah ﷺ must accept it with full submission. If he does not grasp the underlying wisdom, he should attribute that to the limits of human understanding, for all of Allah’s rulings are founded on benefit. Allah Most High says, “You have been granted but little knowledge” (Q 17:85). As for evil or suspicious thoughts, he must repel them, for they come from Satan’s whispering.

Disagreement among the jurists
Imām al-Shāfiʿī and the majority maintain that after every sleep, whether by night or by day, it is prescribed to wash the hands. This is based on the general phrase “from his sleep,” an indefinite noun in a genitive construction that encompasses every kind of sleep. The expression “where his hand spent the night” is merely a prevailing restriction (qayd aghlabī); and when a restriction is of that nature, the uṣūl scholars hold that it carries no legal implication. Allah the Exalted says, “And your step-daughters who are in your care, born of your wives with whom you have consummated marriage…” (Q 4:23). In that verse two restrictions appear: first, “with whom you have consummated marriage,” an intentional condition whose converse is spelled out in His words, “But if you have not consummated…,” and second, “who are in your care,” a prevailing condition that therefore yields no separate ruling.