[1] Medically it is well-known now that a fly carries some pathogens on some parts of its body as mentioned by the Prophet (ﷺ) (before 1400 years approx. when the humans knew very little of modem medicine.) Similarily Allah created organisms and other mechanisms which kill these pathogens e.g. Penicillin Fungus kills pathogenic organisms like Staphylococci and others etc. Recently experiments have been done under supervision which indicate that a fly carries the disease (pathogens) plus the antidote for those pathogenic organisms. Ordinarily when a fly touches a liquid food it infects the liquid with its pathogens, so it must be dipped in order to release also the antidote for those pathogens to act as a counterbalance to the pathogens. Regarding this subject I also wrote through a friend of mine to Dr. Muhammad M. El-Samahy, chief of Hadith Dept. in Al-Azhar University, Cairo (Egypt), who has written an article upon this HadIth and as regards medical aspects, he has mentioned that the microbiologists have proved that there are longitudinal yeast cells living as parasites inside the belly of the fly and these yeast cells in order to repeat their life cycle protrude through respiratory tubules of the fly and if the fly is dipped in a liquid, these cells burst in the fluid and the content of those cells is an antidote for the pathogens which the fly carries.