We’re all familiar with this scientific error from Sunan Abu Dawud, which I often use in my debates:
Sunan Abu Dawud 67–I heard that the people asked the Prophet of Allah (peace be upon him): Water is brought for you from the well of Buda’ah. It is a well in which dead dogs, menstrual cloths and excrement of people are thrown. The Messenger of Allah (peace be upon him) replied: Verily water is pure and is not defiled by anything.
Things get worse, however. In the following passage from Ibn Majah, we learn that it’s okay to drink water with a dead donkey carcass floating in it!
Sunan Ibn Majah 520–It was narrated that Jabir bin Abdullah said: “We came to a pond in which there was the carcass of a donkey, so we refrained from using the water until the Messenger of Allah came to us and said: ‘Water is not made impure by anything.’ Then we drank from it and gave it to our animals to drink, and we carried some with us.”
And let’s not forget this gem:
Sunan Ibn Majah 521–It was narrated that Abu Umamah Al-Bahili said: “The Messenger of Allah said: ‘Water is not made impure by anything except that which changes its smell, taste and color.'”
This is, of course, totally false. Water can be filled with deadly germs that do not affect smell, taste, or color.
Let’s conclude with a classic:
Sahih al-Bukhari 5782–Allah’s Messenger said, “If a fly falls in the vessel of any of you, let him dip all of it (into the vessel) and then throw it [i.e. the fly] away, for in one of its wings there is a disease and in the other there is healing (antidote for it) i.e. the treatment for that disease.”
If I were a Muslim looking for something miraculous to justify Islam, I would argue that it was miracle that Muhammad’s followers didn’t all die from the germs and diseases he exposed them to with his horribly unsanitary rulings.