Does sleep invalidate the ablution, and what is the explanation for the action of the Companions, who used to sleep and then rise to pray?

The questioner : 'Umar (may Allah be pleased with him) in a hadith in the Fiqh al-Sunnah that we read, in the meaning of the hadith, that the Messenger (peace and blessings be upon him) was delayed, so he began to speak, the prayer was established, and he was occupied with the prayer until some of the Companions dozed off. I do not remember if they slept or if some of them slept, and then he came and completed the prayer, meaning he prayed in the interval that passed between the establishment of the prayer and the performance of the prayer, in which some of the people dozed off. This hadith has passed you by.The Shaykh : This is authentic.

The questioner : It is authentic that they dozed off.

The Shaykh : The dozing is not the problem; the problem is sleep, because dozing does not invalidate the ablution. There is no issue with dozing alone; dozing does not invalidate the ablution. What invalidates it is sleep. And indeed, there are authentic hadiths stating that they did not just sleep, but they would lie down until the sound of one of them could be heard, and then they would rise to the prayer. Because you know that the rulings did not come all at once, but they came gradually. They used to sleep, and even become heavy in sleep, and then rise to the prayer. This was the case, but the ruling later settled on the saying of the Messenger (peace and blessings be upon him) and therefore he said So it is sleep that settled as invalidating the ablution, not dozing. But sleep was not invalidating the ablution in the early days of Islam, except later. Therefore, if you find such an incident, attribute it to the earlier practice. But here is a matter of precision: what is the criterion between sleep and dozing? Because most people do not know this issue, even though it is very important. The one who slept must renew the ablution, and the one who dozed does not have to renew the ablution. The best that has been said in this area is that dozing is when the dozer does not lose hearing of the sounds around him, but he loses consciousness and understanding. He is alert and hears that there is a sound, but he is not awake enough to understand that speech. If the sound is lost to him, then he has slept. This is what invalidates the ablution. This is the criterion and the difference between dozing and sleep.