What is the foundation of Judaism?
1. It is based on the covenants established by Hashem (God) with our ancestors. Avraham, Isaac and Jacob. This is what gives legality to our patriarchs.Â
 2. He is the only people with whom Hashem (God) made a covenant, putting a sign in the flesh circumcision. “National pact and irreversible exclusive to Israel”. Bereshit Genesis 17:1-8.
1. He was Abram of ninety-nine years old, when Jehovah appeared to him and said to him, “I am the Almighty God; walk before me and be perfect.2. And I will put my pact between me and you, and I will multiply you in a great way.3. Then Abram bowed down on his face, and God spoke to him, saying:4. Behold my covenant is with you, and you will be father of a crowd of people.5. And it will not be called your name Abram anymore, but it will be your name Abraham, because I have made you father of crowd people.6. And I will multiply you greatly, and I will make nations of you, and kings will come out of you.7. And I will establish my covenant between me and you, and your offspring after you in their generations, by perpetual covenant, to be your God, and that of your offspring after you.8. And I will give to you, and to your offspring after you, the land in which you dwell, all the land of Canaan in perpetual inheritance; and I will be the God of them.
Perpetual Covenant Established by Hashem (God). Bereshit 17:11-14.
11. So you shall circumcise the flesh of your foreskin, and it will be by sign of the covenant between me and you.12. And at the age of eight days will be circumcised every male among you for your generations; the one born at home, and the one bought for money from any foreigner, who is not your lineage. The one born in your house must be circumcised, and the one bought for your money; and my covenant will be in your flesh by perpetual covenant.14. And the uncircumcised male, who has not circumcised the flesh of his foreskin, that person will be cut off from his people; he has violated my covenant.