|Malik||Person who sleeps reclining on his side or prostrate must perform ablution (where sleep was long or short)||Imam Malik excluded the person who sleeps in a sitting posture.
The hadith of Abu Huraira shows that sleep necessitates ablution whether long or short.
Since sleeping can be a cause of annulment of ablution only on account of the fact it makes it easy the release of cause of hadath. Malik took into account three factors: soundness, duration and posture. He didn't stipulate either duration or soundness for postures that usually facilitate the occurrence of hadath, but did for postures that normally don't do so like standing or sitting.
|Shafi||Whenever the person sleeps, whatever his posture, he is obliged to perform ablution||Imam Shafi excluded the person who dozes of while sitting because Companions used to sleep while sitting and then used to pray without performing ablution.
Hadith of Safwan ibn Assal shows that prophet (SAW) held urination, visit to privy and sleep to be similar.
|Hanifa||There is no ablution required for a person who sleeps, except for one sleeping on this side.||Hadith of Ibn Abbas, Hadith of Aisha and it is also related that the companions of the Prophet (SAW) used to doze off in the mosque till their heads would sink low. They prayed after this without performing ablution.
Based on the marfu tradition from Umar, Imam Hanifa made it obligatory to perform ablution only after sleep while reclining on the side
|Majority||Ablution is only required for extended sleep and not for long sleep||Using the method of reconciliation, the traditions prescribing ablutions apply to extended sleep while traditions waiving ablution apply to short sleep.|