Question 158: The Messenger of Allaah (peace be upon him) said: When any of you wakes up from sleep, he must not put his hand in the bowl (of water) until he has washed it three times, for he does not know where his hand was during the night. (Related by Muslim)
Does a person placing his hand in a bowl containing water upon waking up at night defile the purity of the water, in which case he will not be permitted to perform Wudoo’ (ablution) with it? Or does it maintain its state of purity, and therefore it will be permissible for him to perform Wudoo’ with it? Which is correct and preferable? We appreciate your advice. May Allaah reward you with the best.
Answer: All praise be to Allaah Alone, and peace and blessings be upon His Messenger, and his family and Companions. Compliance with the prohibition stated in this Hadeeth is Ta`abbudee (a devotional obedience; the reason of its legislation lies beyond rational analysis). A person placing his hand in water upon waking up does not necessarily defile the purity of the water. The correct opinion is that it is permissible to perform Wudoo’ with such water… read more here.