It was the beginning of a Divine supernatural agency which would continue to operate throughout the history of the chosen people of God. He was not only the child of the Covenant, but the supernatural element in his birth was a sign of the Divine in the development and fulfillment of the Covenant of Redemption for man.
Greatest of all, the miraculous birth of I'saac was prophetic of a still greater supernatural birth which was to take place in the future A'bra-ham'ic family. It foretold the miracle by which God would bring "His first-begotten" into the world. As in the case of I'saac, the birth of Jesus was announced long before it took place, the name was given prior to the birth, and the birth occurred at a time appointed by God. In both cases the beginning of a greater Is'ra-el in the world was marked by a miraculous birth.
Sa'rah's visitation recalls that Ma'ry, the Mother of Je'sus, though there were differences. Sa'rah gave birth when she was old and the natural faculties of child-bearing were dead, while Ma'ry was little more than a child herself. Sa'rah's child was to be the father of natural Is'ra-el; the Son of Mary was to be the founder of spiritual Is'ra-el.
The birth of I'saac was the occasion for the first cradle hymn of history, the song of Sa'rah being the first of its kind of literature. It was a hymn of wonder and joy in supreme acknowledgment of the gift of God, and a song in which her relatives and friends heartily joined in singing. It was a song of the greatness that was to come for her son, and of the hope for countless descendants.
