The rejection of Aahaad hadeeth in aqidah is a standard Mu'tazili, Ash'ari doctrine and it is found in their textbooks on creed. Through this doctrine, they reject what does not agree with the intellect (that is their intellects), despite the fact that all the great Muslim specialist scholars are unanimously agreed that if a hadeeth is authentic (saheeh, hasan), regardless of whether it is mutawaatir or aahaad, it is from the religion and it is obligatory to accept it in both affairs of knowledge and action, and as for whether it provides certain knowledge, then when the Ummah has united upon it, such as what is found in Bukhaaree and Muslim, then it amounts to certain knowledge, and much of what these Innovators reject are from the agreed upon aahaadeeth in Bukhaaree and Muslim. Scholars like Ibn Hajar and an-Nawawi, despite being affected by something of the Ta'weel of the Ash'aris rejected this false Mu'tazili, Ash'ari doctrine.

This doctrine is stated explicitly by the Ash'aris and Maturidis of early 20th century Egypt such as Sayyid Qutb and Muhammad Abduh.

Muhammad Abduh wrote in his "Tafseer of Juz 'Ammaa" (p. 182)

That which is obligatory to believe is that the Qu'ran provides certain definitive [knowledge] and that it is the Book of Allaah through at-tawaatur (large-scale, successive transmission) from the infallible [Prophet] (sallallaahu alayhi wasallam). This is what is obligatory to believe in, [to believe in ] what it affirms and to not believe in what it negates. And [the Qur'an] has come with the negation from him (alayhis salaam) of magic [being done upon him] when it attributed the saying of affirming that magic was done to him, to the Mushriks, his enemies. It rebukes them for this claim of their's. Therefore, he was not under the spell of magic, absolutely. And as for the hadeeth, then assuming that it is authentic, it is aahaad, and the aahaad (hadeeths) are not to be taken in the subject of beliefs (aqaa'id) and the innocence of the Prophet from the affect of magic upon his intellect is one of the beliefs whose negation cannot be accepted except by [that which provides] certain truth [al-yaqeen],and it is not permissible that it (the negation of this matter of belief) be accepted by way of presumed and supposed truth, upon [the understanding] that the hadeeth that reaches us by the route of aahaad (solitary transmission) amounts (only) to presumed truth (dhann) for the one to whom it is deemed authentic. As for the one for whom evidences are established that it is not authentic, then proof is not established through it (for him). Whatever the case, it is for us, rather it is upon us that we relegate the affair in [the matter] of the hadeeth and that we do not judge by it in our aqidah, and that we take by the text of the Qur'an and with the evidence of the intellect...

Sayyid Qutb said in his commentary on Surah al-Falaq, (Fi Zilal il-Qur'an 6/4008):

There are reports that have been related - some of them authentic however they are not mutawaatir - that Labeed bin al-A'sam the Jews, did magic upon the Prophet (sallallaahu alayhi wasallam) - in al-Madinah. It is said for [a period of] days, and it is said for months, [to such a degree] that he would be made to imagine that women had come to him and they had not come to him in a narration, and until it he was made to imagine that he had done something he had not done in another narration. And that the two Surahs were revealed as a ruqyah for the Messenger of Allaah (sallallaahu alayhi wasallam) - so when he visualized that magic - as he informed from his dream - and read the two surahs, the magic was broken, and the evil departed from him.

However, these narrations oppose the prophetic infallibility in both actoin (fi'l) and tabligh (conveyance of the message), and they cannot remain compatible with the belief that every action amongst his actions (sallallaahu alayhi wasallam) and every saying from his sayings, in both the Sunnah and the Sharee'ah, just as they clash with the negation of the Qur'an from the Messenger (sallallaahu alayhi wasallam) [that] magic was done upon him, and [the Qur'an's] declaration of the pagans to be liars in what they used to claim regarding this lie. Subsequently, these narrations are far-fetched. And the aahaad hadeeth are not taken in the affairs of aqidah, and source is the Qur'an and at-tawaatur (successive, large-scale transmission) is a condition for accepting the ahaadeeth in the foundations of belief, and these narrations are not from the mutawaatir.

The ahaadeeth that this Ash'ari is speaking about concerning Labeed bin al-A'sam are taken with acceptance by the entire Ummah and they are related by:

• Imaam Bukhaaree in "Kitab ut-Tibb", "Bab us-Sihr" - twice
• Imaam Bukhaaree in "Kitab ut-Tibb", "Bab Hal Yustakhruj as-Sihr"
• Imaam Bukhaaree in "Kitab ul-Adab"
• Imaam Bukhaaree in "Kitab ud-Da'awaat"
• Imaam Muslim in "Kitaab us-Salaam", "Baab us-Sihr"
• An-Nasaa'ee in "Kitab ut-Tibb", "Bab us-Sihr" - twice
• Imaam Ahmad in his Musnad

However, as you have seen in both quotations from these two individuals (one Ash'ari, and one Maturidi), this issue of aahaad hadeeth is not restricted to the incident of magic being performed upon the Prophet (alayhis salaam) but rather a general principle they speak with in the affairs of the creed. This is alongside the fact that the book of Sayyid Qutb is propagated to this day with such great momentum and vigour with the incorrect comparison between Qutb and the likes of Ibn Hajar and an-Nawawi, being used as an item of propaganda in this regard. Those genuine scholars did not reject aahaad hadeeth in aqidah upon this false principle, this is because they had ilm and they were true scholars, unlike these ignoramuses of the twentieth century.