A study refuting the objections of the heretics to this ḥadith:
Some heretics have disparaged this report, and their censure has even reached Abu Hurayrah. Among them is Mahmūd Abū Rayyah, in his book entitled “Aḍwāʾ ʿalā al-Sunnah al-Muḥammadiyyah” (Lights on the Prophetic Sunnah). He was answered by the eminent scholar ʿAbd al-Raḥmān ibn Yaḥyā al-Muʿallimī in his work “al-Anwār al-Kāshifah”. Al-Muʿallimī wrote: “A book compiled by Abū Rayyah came into my hands. I read it carefully and reflected upon it, and I found it to be nothing but a compilation, arrangement, and completion of the assaults on the Prophetic Sunnah.” The reply to the criticism of this ḥadith is summarised in the following points:
First: The ḥadith before us is one that Imām al-Bukhārī selected for its soundness and placed in his Ṣaḥīḥ. That alone is sufficient, for this noble imām and his book have been unanimously welcomed by the ummah, which has received it with approval, reliance, and practical implementation.
Second: The ḥadith of the fly is not unique to Abu Hurayrah. It is also narrated by Abu Saʿid al-Khudrī and Anas ibn Mālik, as found in the Musnad of Imām Aḥmad (3/24).
Third: Who would dare to malign even the hem of a Companion of the Messenger of Allah ﷺ—let alone the Companion most diligent in preserving and transmitting his ḥadith, the one for whom the Prophet ﷺ prayed that he would retain what he heard and be slow to forget? Abu Hurayrah devoted himself entirely to memorising ḥadith: no farming distracted him, no trade diverted him; day and night he followed every word of wisdom uttered by the Prophet ﷺ, then spent his nights awake, fixing those words firmly in his heart.
Fourth: Shaykh ʿAbd al-Raḥmān ibn Yaḥyā al-Muʿallimī said: “Natural scientists admit that their knowledge is not all-encompassing and that they are continually making fresh discoveries. On what grounds, then, do Abū Rayyah and his peers deny that Allah could have informed His Messenger ﷺ of something that science has not yet reached—especially when the Creator and Governor of nature is the very One who laid down the Sacred Law?”
Fifth: Modern physicians have confirmed that one wing of the fly carries disease while the other carries a remedy. Praise be to Allah—truth has become clear: “And who is more truthful in speech than Allah?” (Qurʾān 4:87).