He prayed after sleeping without making Wudhu'

Question :

I saw one of the Hajj pilgrims sleeping while lying down after praying the night prayer, and he was sleeping deeply; then when the time came for the morning prayer, he woke up and prayed it without renewing his Wudhu. What is the ruling on this prayer?

Answer:

If the matter occurred as you say, that he lay down in deep sleep after praying, then his ablution was nullified, according to the correct opinion of the scholars on the matter. Based upon this, the prayer which he performed after that sleep without ablution is invalid, based upon the narration of Ahmad, Abu Dawud and Ibn Majah, on the authority of 'Ali, may Allah be pleased with him, in which he said: Allah's Messenger said:
"The eye is the drawstring of the anus, so whoever sleeps should make Wudhu'.

As for the narration of Abu Dawud, on the authority of Anas, may Allah be pleased with him, in which he said: "The Companions of Allah's Messenger used to wait for the 'Isha' prayer until their head were nodding, then they would pray without making Wudhu'." it concerns light sleep, reconciling between the Hadiths.

So (we may say that) light sleep does not invalidate ablution. This view is also strengthened by the general import of the Hadith of Safwan bin 'Asal, may Allah be pleased with him, in which he says: "Allah's Messenger ordered us to not to remove our leather socks for three days and nights when we were travelling, unless we were in a state of major impurity (Al- Janabah), but due to defecation or urination (we need not do so)." And through Allah is success achieved. And may peace and blessings be upon Muhammad and upon his family and Companions.

Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 2 Pages 52-53