The brit milah or bris of a newborn boy is both a great mitzvah (commandment) and a great simchah (celebration). The first commandment given to humanity in the Hebrew Bible is pru ur’vu, “be fruitful and multiply.” According to tradition, the second true mitzvah given in the Torah, and the first to be given to our ancestor Abraham, was that of circumcision. Indeed, the Shulchan Aruch, the traditional Code of Jewish Law, starts its section on milah (circumcision) with the statement that this mitzvah is more fundamental and important than any other positive commandment in the entire Torah.
The command to circumcise is given twice. In Genesis 17:10-12 we are told that “G-d said to Abraham: ‘This is my covenant which you are to keep, between me and you and your seed after you: every male among you shall be circumcised. You shall circumcise the flesh of your foreskin, so that it may serve as a sign of the covenant between me and you. At eight days old, every male among you shall be circumcised, throughout your generations…’” Later, in Leviticus 12:1-3, G-d commands all the Israelites that “…a woman–when she produces seed and bears a male child…on the eighth day, the flesh of his foreskin is circumcised.”
Genesis 17 begins with G-d’s commandment to Abram that he is to “Walk in My presence and be perfect (tamim)! The Rabbis understand this to mean that only after circumcision is Abraham considered perfect. So too, a new baby is considered “perfect” or “whole” only after we have joined in G-d’s act of creation by committing the baby to the covenant by this action of circumcision. Abraham circumcised his son Isaac at the age of eight days, and Jewish boys have traditionally been welcomed into our people by means of this covenant ever since.

