Treasury of Scripture Knowledge
Notice therefore that those who possess faith are true sons of Abraham.
But you, brethren, like Isaac, are children born in fulfilment of a promise.
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;