Is it obligatory to wash the hands three times when performing ablution immediately after waking up from sleep, and what is the ruling on someone who washed his hands before the time for prayer began, then performed ablution when the time for prayer commenced?

Washing the hands up to the elbows three times is a Sunnah when beginning ablution. As for washing them once from the fingertips to the elbows, that is obligatory (fard), and the second and third washes are recommended (mustahabb).

If a sleeper awakens and intends to perform ablution, it is sunnah for them to wash their hands three times, and it is disliked to immerse them in a vessel before doing so, due to the fear of impurity. This prohibition is considered by the majority to be one of dislike and purification (karahah wa tanzeeh), so washing them is recommended and not obligatory.

The Hanbalis, however, view washing them as obligatory after night sleep, based on the saying of the Prophet, peace and blessings be upon him: "When one of you wakes up from his sleep, he should not dip his hand into the vessel until he washes it three times, for he does not know where his hand spent the night."

If a person washes their hands after waking up from sleep for a reason other than ablution, and then wishes to perform ablution, it is recommended for them to wash their hands according to everyone.