God commanded the ceremony of circumcision for Abraham and his descendants.

Acts 7:8

8 “Then God commanded Abraham that every male in his household and all of his male descendants should be circumcised to show that they all belonged to God and that they would obey what he had told Abraham to do. Later Abraham’s son, Isaac, was born, and when Isaac was eight days old, Abraham circumcised him. Later Isaac’s son, Jacob, was born, and Isaac similarly circumcised him. And Jacob similarly circumcised his twelve sons. They are the twelve men from whom we(inc) Jews have all descended.”