In Genesis 17:12, God commanded Abraham to circumcise baby boys on the eighth day of their lives. Why day eight? Is there any good, scientific rationale behind such a command
In Genesis 17:12, God specifically directed Abraham to circumcise newborn males on the eighth day. Why the eighth day? In 1935, professor H. Dam proposed the name “vitamin K” for the factor in foods that helped prevent hemorrhaging in baby chicks. We now know vitamin K is responsible for the production (by the liver) of the element known as prothrombin.
If vitamin K is deficient, there will be a prothrombin deficiency and hemorrhaging may occur. Oddly, it is only on the fifth through the seventh days of the newborn male’s life that vitamin K (produced by bacteria in the intestinal tract) is present in adequate quantities.
Vitamin K, coupled with prothrombin, causes blood coagulation, which is important in any surgical procedure. Holt and McIntosh, in their classic work, Holt Pediatrics, observed that a newborn infant has “peculiar susceptibility to bleeding between the second and fifth days of life.... Hemorrhages at this time, though often inconsequential, are sometimes extensive; they may produce serious damage to internal organs, especially to the brain, and cause death from shock and exsanguination” (1953, pp. 125-126).
Obviously, then, if vitamin K is not produced in sufficient quantities until days five through seven, it would be wise to postpone any surgery until some time after that. But why did God specify day eight?
On the eighth day, the amount of prothrombin present actually is elevated above one-hundred percent of normal—and is the only day in the male’s life in which this will be the case under normal conditions. If surgery is to be performed, day eight is the perfect day to do it. Vitamin K and prothrombin levels are at their peak