The Qur’an was revealed 600 years before the Muslim scientist Ibn Nafees described the circulation of the blood and 1,000 years before William Harwey brought this understanding to the Western world. Roughly thirteen centuries before it was known what happens in the intestines to ensure that organs are nourished by the process of digestive absorption, a verse in the Qur’an described the source of the constituents of milk, in conformity with these notions

To understand the Qur’anic verse concerning the above concepts, it is important to know that chemical reactions occur in the intestines and that from there, substances extracted from food pass into the blood stream via a complex system; sometimes by way of the liver, depending on their chemical nature. The blood transports them to all the organs of the body, among which are the milk-producing mammary glands.

In simple terms, certain substances from the contents of the intestines enter into the vessels of the intestinal wall itself, and these substances are transported by the blood stream to the various organs.