A drowsy person whom sleep has overtaken, and a state of slumber has settled in his eye, yet he is not sleeping.

And because that which nullifies is the loss of consciousness, and whenever the intellect is stable and one's senses have not ceased—such as one who hears what is being said around him and understands it—the cause for nullification does not exist in his case. If one doubts whether he slept or not, or if something crosses his mind and he does not know if it was a dream or a self-conversation, then he is not required to perform wudu'.

45 - Issue; he said: (And apostasy from Islam)

The entirety of this is that apostasy nullifies wudu' and invalidates tayammum. This is the view of al-Awza'i and Abu Thawr. Apostasy is the commission of that which causes one to exit the fold of Islam, whether through speech, belief, or a doubt that removes one from Islam. So, whenever one returns to his Islam and reverts to the religion of truth, he may not pray until he performs wudu', even if he was in a state of wudu' before his apostasy. Abu Hanifa, Malik, and al-Shafi'i said: Wudu' is not invalidated by that. Al-Shafi'i has two reports regarding the invalidation of tayammum by it, due to the saying of Allah the Almighty: {And whoever of you reverts from his religion and dies while he is a disbeliever—for those, their deeds have become worthless} (1). He thus stipulated death, and because it is a state of purity, it is not invalidated by apostasy, just like ghusl (major ritual washing) from janaba (ritual impurity). Our argument is His, the Almighty's, saying: {If you associate others with Allah, your deeds will surely become worthless} (2). Purity is a deed, and it remains in effect in terms of its legal ruling, being invalidated by its nullifiers, so it must be rendered worthless by shirk (associating partners with Allah). Also, it is an act of worship that is corrupted by hadath (ritual impurity), so it is corrupted by shirk, like prayer and tayammum. Furthermore, apostasy is a hadath, based on the statement of Ibn 'Abbas: "Hadath is of two types: hadath of the tongue and hadath of the private part, and the more severe of the two is the hadath of the tongue." When one incurs hadath, his prayer is not accepted without wudu', due to the Prophet's (peace and blessings of Allah be upon him) statement: "Allah does not accept the prayer of any of you when he incurs hadath until he performs wudu'." It is agreed upon (3). What they mentioned is an adherence to the 'dalil al-khitab' (implication of the text).