The customs and laws pertaining to circumcision are derived from the Bible, Talmud, and Jewish tradition, all of which have been meticulously passed down from generation to generation.
God's First Commandment to Abraham
Circumcision is the first commandment given by God to Abraham, the first Jew, and is central to Judaism. Abraham, the father of the Jewish People, had for many years served God righteously. Yet it was only after he circumcised himself by God's command at the age of ninety-nine years, that he was able to reach the ultimate level of Biblical perfection of "and you shall be perfect" (Genesis 17:1).
God desired that this final "finishing touch" and perfection of our body should be a distinctly human act. This teaches us that spiritual perfection must and can be accomplished by human effort.