God made this promise to Abraham several times. At one point, God linked the promise with two key things: a name change, and circumcision. Abraham, who had been known as Abram, was given his new name. Abraham’s wife, Sarah, who had been known as Sarai, was given her new name. Circumcision, the surgical removal of the foreskin of the penis, became for all of Abraham’s male descendants an indication of commitment to the one and only God. God specified that from that point forward, all male descendants of Abraham should be circumcised at eight days old. Abraham and the other males who were already past eight days old had their circumcisions retroactively.