35 – On the authority of Abū Hurayrah d. AH, who said: The Messenger of Allah ﷺ said, “When any one of you wakes up from his sleep, he must not dip his hand into the vessel until he has washed it three times, for he does not know where his hand spent the night.” Agreed upon, and this is Muslim’s wording (1).

Vocabulary of the ḥadith
– idha istayqaza: ‘he awoke from his sleep’. The verb istayqaẓa means “to become alert”; it is intransitive. Idha is a conditional particle that does not govern the jussive; its apodosis is “so let him not immerse his hand”.
– la yaghmis: from ghamasa, yaghmisu (to immerse) — i.e. he is not to put his hand into the water.
– yadahu: “his hand”; here it means the palm, which includes the palm proper and the fingers. Its limits are from the fingertips to the wrist.
– fa-lā yaghmis yadahu: ghams is to plunge the hand into the water that is in the vessel. Lā is a prohibitive particle and yaghmis is in the jussive because of it. Some versions in al-Bukhārī read fa-lā yaghmisann-a with the emphatic nūn.
– fa-innahu lā yadrī: an indication that the rationale for the command is the possibility of impurity; whenever the Lawgiver mentions a ruling and follows it with its reason, the ruling is understood to rest upon that reason.
– ayna: an adverb of place, built on fatḥ and in the accusative position. The place in question may be some part of the sleeper’s own body, or it may refer to the hand’s contact with Satan.

Points derived from the ḥadith
1 – It is obligatory to wash both hands three times after waking from night-sleep; one or two washings do not suffice. When the term “hand” is left unrestricted, it refers only to the palm, not the forearm. This is the view of Imām Aḥmad, while the majority hold it to be recommended rather than obligatory.