in cattle there is a lesson for yon. I give you drink from their
insides, coming from a conjunction between the digested contents ( of
the intestines ) and the blood, milk pure and pleasant for those who
drink it." Qur'an, 16:66
In the field of physiology, there is one verse which appears extremely
significant to me. One thousand years before the discovery of the blood
circulatory system, and roughly thirteen centuries before it was determined that
the internal organs were nourished by the process of digestive , a verse in the
Qur'an described the source of the constituents of milk, in conformity with
To understand this verse, it must first be known that chemical reactions occur
between food and enzymes in the mouth, the stomach and the intestines releasing
nutrients in molecular form which are then absorbed into the circulatory system
through countless microscopic projections of the intestinal wall called villi.
Blood in the circulatory system then transports the nutrients to all the organs
of the body, among which are the milk-producing mammary glands.
This biological process must be basically understood, if we are to understand a
verse in the Qur'an which has for many centuries given rise to commentaries that
were totally incomprehensible.
Today it is not difficult to see why! This verse is taken from the chapter an-Nahl:
"Verily, in cattle there is a lesson for yon. I give you drink from their
insides, coming from a conjunction between the digested contents ( of the
intestines ) and the blood, milk pure and pleasant for those who drink it."
The constituents of milk are secreted by the mammary glands which are nourished
by the product of food digestion brought to them by the bloodstream. The initial
event which sets the whole process in motion is the conjunction of the contents
of the intestine and blood at the level of the intestinal wall itself.
This very precise concept is the result of the discoveries made in the chemistry
and physiology of the digestive system over one thousand years after the time of
Prophet Muhammad (S).