and how excellent is what has been said: if you do not know, then that is a calamity, and if you do know, then the calamity is greater. Then many people imagine that this ḥadīth contradicts what doctors assert, which is that flies carry germs on their extremities, and if they land in food or drink, those germs cling to it. The truth is that the ḥadīth does not contradict the doctors in this regard, rather it supports them as it informs that in one of its wings there is disease, but it adds to their knowledge by saying: "and in the other there is a cure." This is something they have not fully comprehended, so it is obligatory for them to believe in it if they are Muslims, otherwise to withhold judgment if they are not, provided they are rational scholars! This is because true knowledge testifies that the absence of knowledge about something does not necessitate knowledge of its nonexistence. We say this assuming that modern medicine has not confirmed the ḥadīth's validity, as doctors' opinions have differed on it, and I have read many articles in various journals, each supporting or refuting it. As believers in the authenticity of the ḥadīth and that the Prophet (ṣallá Allāhu ʿalayhi wa-sallam) "does not speak from [his own] desire. It is only a revelation revealed" (Sūrah al-Najm, 53:3-4), it does not concern us much whether the ḥadīth is proven from a medical perspective, because the ḥadīth is a self-evident proof that does not require external support. Nevertheless, one's faith increases when they see the authentic ḥadīth agreeing with true science, and therefore it is beneficial to convey to the readers a summary of a lecture given by a doctor at the Islamic Guidance Society in Egypt about this ḥadīth. He said: "Flies land on filthy materials filled with germs that cause various diseases, transferring some with their extremities and consuming some, resulting in a toxic substance forming in their bodies