Romans 4:11

Before, not after. And he received circumcision as a sign, a mark attesting the reality of the faith-righteousness which was his while still uncircumcised, that he might be the forefather of all those who believe even though they are uncircumcised--in order that this righteousness might be placed to their credit;

Acts 7:8

"Then He gave him the Covenant of circumcision, and under this Covenant he became the father of Isaac--whom he circumcised on the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve Patriarchs.

Treasury of Scripture Knowledge

Summary

And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you.

Bible References

A token

Acts 7:8
"Then He gave him the Covenant of circumcision, and under this Covenant he became the father of Isaac--whom he circumcised on the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve Patriarchs.
Romans 4:11
Before, not after. And he received circumcision as a sign, a mark attesting the reality of the faith-righteousness which was his while still uncircumcised, that he might be the forefather of all those who believe even though they are uncircumcised--in order that this righteousness might be placed to their credit;
Acts 7:8
"Then He gave him the Covenant of circumcision, and under this Covenant he became the father of Isaac--whom he circumcised on the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve Patriarchs.
Romans 4:11
Before, not after. And he received circumcision as a sign, a mark attesting the reality of the faith-righteousness which was his while still uncircumcised, that he might be the forefather of all those who believe even though they are uncircumcised--in order that this righteousness might be placed to their credit;