Romans 4:11

4:11 And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised, so that he would become the father of all those who believe but have never been circumcised, that they too could have righteousness credited to them.

Romans 4:13

4:13 For the promise to Abraham or to his descendants that he would inherit the world was not fulfilled through the law, but through the righteousness that comes by faith.