God commanded Abraham to circumcise newborn males on the eighth day. Why that day? Blood clotting depends heavily upon two nutrients: vitamin K and prothrombin. A baby boy’s body does not produce adequate levels of vitamin K until days 5-7. On the eighth day, prothrombin is elevated high above 100% of normal. This is the only day in a male’s life that this will occur. A medical doctor once observed, “Abraham did not pick the eighth day after many centuries of trial and error…it was a day picked by the Creator of vitamin K” (McMillen 21). Who better understands the function of a machine than its inventor? It wasn’t a lucky guess. It was a divine command made through the perfect knowledge of God.
McMillen, S.I. None of These Diseases. 1963.)