Genesis 17:1; Genesis 17:3; Genesis 17:11; Genesis 17:14

1 When Abram was ninety-nine years old, the LORD appeared to him and said, "I am God Almighty; serve me faithfully and live a blameless life.
3 At this, Abram fell face down in the dust. Then God said to him,
11 the flesh of his foreskin must be cut off. This will be a sign that you and they have accepted this covenant.
14 Anyone who refuses to be circumcised will be cut off from the covenant family for violating the covenant."