How is Isaac connected with the ancestry of the Jewish people?

In the Hebrew Bible, Isaac is the second of the Hebrew patriarchs and the son of Abraham and Sarah. He is central to the ancestry of the Jewish people because the covenant God established with Abraham—promising that his "seed" would inherit the land and become a great nation—is understood in Judaism to be fulfilled through Isaac.12

Isaac serves as the vital link in the lineage of the patriarchs. As the father of Jacob, who is the traditional ancestor of the Twelve Tribes of Israel, Isaac ensures the continuity of God’s promise and purpose. Furthermore, in both the Old and New Testaments, God is frequently referred to as the "God of Abraham, Isaac, and Jacob," signifying that the divine relationship was fixed for all their descendants. While Abraham is revered as the first patriarch, Isaac is the essential successor through whom the Jewish people trace their heritage and their connection to the divine covenant.3124