Thirteen years after the incident of Hagar's birth of Ishmael to Abram, God returns to him and issues a sign of the covenant: circumcision. He changes Abram's and Sarai's names and goes on to inform Abraham that Ishmael is NOT the promised seed. God will give him another son, and that son (Isaac) will be the son of promise. Abraham ultimately believes God and in obedience is circumcised along with all the males of his household.