That two peoples were foretold, the eider and the younger; that is, the old people of the Jews, and the new one which should consist of us
In Genesis: “And the Lord said unto Rebekah, Two nations are in your womb, and two peoples shall be separated from your belly; and the one people shall overcome the other people; and the elder shall serve the younger.” Also in Hosea: “I will call them my people that are not my people, and her beloved that was not beloved. For it shall be, in that place in which it shall be called not my people, they shall be called the sons of the living God.”
Source: The Treatises of Cyprian (New Advent)