Seeker and Methe, I will release you from your suffering. It is mentioned in the book of J (Genesis)
Genesis 17, The Lord appeared to Abraham when he was ninety-nine years old and made a covenant with him, agreeing that he would be the God of the Jews and the Jews would worship no other god but him.
?For Your part, you must keep my covenant, you and your descendants after your, generation by generation. This is how you shall keep my covenant between myself and your descendants after you: circumcise yourselves every male among you. You shall circumcise the flesh of your foreskin, and it shall be the sign of the covenant between us. Every male among you in every generation shall be circumcised on the eighth day, both those born in your house and any foreigner, not of your blood but bought with your money. Circumcise both those born in your house and bought with your money.?(genesis 17:9-19)
This is what Sam is referring to, it is a convenant to God.
However, scholars have known for a long time that this passage was never in the original nor in 3 version that were copies of the original. It was added about 500 B.C., over one thousand years after the time of Abraham. Scholars David Rosenberg and Harold Bloom have published a full translation of the original version of Genesis, which dates from about 950 B.C. Here, Chapter 17 is conspicuously absent. All we read is that
?it was that day Yahweh cut a covenant with Abram:?I gave this land to your seed, from the river of Egypt to the great river, Euphrates?of the Kenite, and Kenizzite, the Kadmonite; of Hittite, the Perizzite, the Rephaim; of the Amorite, the Canaanite, the Girashite, the Jubisite(23)?
Does this answer your question? I did try to answer this in a post earlier but I realised maybe I was not clear enough.