Genesis 17:12, The Reason For Circumcision
He who is eight days old among you shall be circumcised, every male child in your generations
//According to the law, males in Israel had to be circumcised on the 8th day of their life. Here is the law again, this time in Leviticus:
And on the eighth day the flesh of his foreskin shall be circumcised. –Leviticus 12:3
But have you ever wondered why? What’s the big deal about going under the knife on the 8th day? Take a look at this verse, where Israelites were instructed to give their firstborn sons to God on the 8th day of their life:
You shall not delay to offer the first of your ripe produce and your juices. The firstborn of your sons you shall give to Me. Likewise you shall do with your oxen and your sheep. It shall be with its mother seven days; on the eighth day you shall give it to Me. –Exodus 22:29-30
What they were supposed to do with that firstborn son is unclear. How is he “given to God”? The animals were sacrificed, but were children? How barbaric!
Perhaps they were though, at least ritually. It is possible that circumcision served as a substitutional ritual of dedication, so that actual killing of the child was unnecessary.