This makes clear that ʿUmar’s words, “The women and children have fallen asleep,” referred to the people waiting for prayer in the mosque. It also shows that when someone waiting for prayer—such as someone waiting for the Friday prayer—falls asleep, whatever the nature of that sleep, his ablution is not invalidated. Sleep itself does not invalidate ablution; rather, what invalidates it is the occurrence of ritual impurity.

When someone sleeps in the usual manner people ordinarily choose—such as sleeping at night or taking a midday nap—he commonly passes wind without being aware of it. Since the underlying reason is hidden and cannot be known, its indicator takes its place: namely, the kind of sleep during which this ordinarily happens.

As for sleep about which one is uncertain whether any wind was passed, it does not invalidate ablution, because ritual purity is established with certainty and is not removed by doubt. There are several views on this issue, which this is not the place to discuss in detail. However, this is the view supported by the evidence. Neither the Quran nor the Sunnah contains a text requiring ablution to be considered invalid after every kind of sleep.

For his saying,

“The eye is the drawstring of the anus; when the eyes sleep, the drawstring comes loose,”

has been reported in the Sunan collections on the authority of ʿAlī ibn Abī Tālib and Muʿāwiyah