Milk production in mammals, a process understood today, was described in the Quran over 1400 years ago. Modern science confirms that milk is produced in mammary glands, which draw nutrients directly from the bloodstream. These nutrients, in turn, are absorbed into the bloodstream from digested food in the gastrointestinal tract.

The mammary glands, specialized exocrine glands in mammals, produce milk to nourish offspring. These glands extract nutrients like proteins, fats, and sugars directly from the bloodstream, which carries digested nutrients absorbed from food. Earlier misconceptions held that milk was derived from fat near the nipples, but this has been disproven through modern biological studies.

The verse accurately describes the connection between digested food, blood, and milk production—a fact that aligns with modern physiology. The process begins with digestion, followed by nutrient absorption into the blood, and finally milk synthesis in the mammary glands.

Modern studies reveal that cow's milk is about 88% water. Remarkably, in the Quranic text of Surah An-Nahl, the words "water" and "milk" in verses 16:65-66 are separated by exactly 88 letters, reflecting this scientific fact.

This precise description of milk's origins and composition in the Quran was revealed during a time when such knowledge was inaccessible. How could an unlettered man, the Prophet Muhammad ﷺ, have known this? For believers, such insights point to the divine origin of the Quran, containing knowledge confirmed by science centuries later.