Isaac was the counterpart of his father in body and soul. He resembled him in every particular--"in beauty, wisdom, strength, wealth, and noble deeds." It was, therefore, as great an honor for Isaac to be called the son of his father as for Abraham to be called the father of his son, and though Abraham was the progenitor of thirty nations, he is always designated as the father of Isaac.
Despite his many excellent qualities, Isaac married late in life. God permitted him to meet the wife suitable to him only after he had successfully disproved the mocking charges of Ishmael, who was in the habit of taunting him with having been circumcised at the early age of eight days, while Ishmael had submitted himself voluntarily to the operation when be was thirteen years old. For this reason God demanded Isaac as a sacrifice when he had attained to full manhood, at the age of thirty-seven, and Isaac was ready to give up his life. Ishmael's jibes were thus robbed of their sting, and Isaac was permitted to marry. But another delay occurred before his marriage could take place. Directly after the sacrifice on Mount Moriah, his mother died, and he mourned her for three years. Finally he married Rebekah, who was then a maiden of fourteen.
Rebekah was "a rose between thorns." Her father was the Aramean Bethuel, and her brother was Laban, but she did not walk in their ways. Her piety was equal to Isaac's. Nevertheless their marriage was not entirely happy, for they lived together no less than twenty years without begetting children. Rebekah besought her husband to entreat God for the gift of children, as his father Abraham had done. At first Isaac would not do her bidding. God had promised Abraham a numerous progeny, and he thought their childlessness was probably Rebekah's fault, and it was her duty to supplicate God, and not his. But Rebekah would not desist, and husband and wife repaired to Mount Moriah together to pray to God there. And Isaac said: "O Lord God of heaven and earth, whose goodness and mercies fill the earth, Thou who didst take my father from his father's house and from his birthplace, and didst bring him unto this land, and didst say unto him, To thee and thy seed will I give the land, and didst promise him and declare unto him, I will multiply thy seed as the stars of heaven and as the sand of the sea, now may Thy words be verified which Thou didst speak unto my father. For Thou art the Lord our God, our eyes are toward Thee, to give us seed of men as Thou didst promise us, for Thou art the Lord our God, and our eyes are upon Thee." Isaac prayed furthermore that all children destined for him might be born unto him from this pious wife of his, and Rebekah made the same petition regarding her husband Isaac and the children destined for her.
Their united prayer was heard. Yet it was chiefly for the sake of Isaac that God gave them children. It is true, Rebekah's piety equalled her husband's, but the prayer of a pious man who is the son of a pious man is far more efficacious than the prayer of one who, though pious himself, is descended from a godless father.
The prayer wrought a great miracle, for Isaac's physique was such that he could not have been expected to beget children, and equally it was not in the course of nature that Rebekah should bear children.
When Rebekah had been pregnant seven months, she began to wish that the curse of childlessness had not been removed from her. She suffered torturous pain, because her twin sons began their lifelong quarrels in her womb. They strove to kill each other. If Rebekah walked in the vicinity of a temple erected to idols, Esau moved in her body, and if she passed a synagogue or a Bet ha-Midrash, Jacob essayed to break forth from her womb. The quarrels of the children turned upon such differences as these. Esau would insist that there was no life except the earthly life of material pleasures, and Jacob would reply: "My brother, there are two worlds before us, this world and the world to come. In this world, men eat and drink, and traffic and marry, and bring up sons and daughters, but all this does not take place in the world to come. If it please thee, do thou take this world, and I will take the other." Esau had Samael as his ally, who desired to slay Jacob in his mother's womb. But the archangel Michael hastened to Jacob's aid. He tried to burn Samael, and the Lord saw it was necessary to constitute a heavenly court for the purpose of arbitrating the case of Michael and Samael. Even the quarrel between the two brothers regarding the birthright had its beginning before they emerged from the womb of their mother. Each desired to be the first to come into the world. It was only when Esau threatened to carry his point at the expense of his mother's life that Jacob gave way.
Rebekah asked other women whether they, too, had suffered such pain during their pregnancy, and when they told her they had not heard of a case like hers, except the pregnancy of Nimrod's mother, she betook herself to Mount Moriah, whereon Shem and Eber had their Bet ha-Midrash. She requested them as well as Abraham to inquire of God what the cause of her dire suffering was. And Shem replied: "My daughter, I confide a secret to thee. See to it that none finds it out. Two nations are in thy womb, and how should thy body contain them, seeing that the whole world will not be large enough for them to exist in it together peaceably? Two nations they are, each owning a world of its own, the one the Torah, the other sin. From the one will spring Solomon, the builder of the Temple, from the other Vespasian, the destroyer thereof. These two are what are needed to raise the number of nations to seventy. They will never be in the same estate. Esau will vaunt lords, while Jacob will bring forth prophets, and if Esau has princes, Jacob will have kings. They, Israel and Rome, are the two nations destined to be hated by all the world. One will exceed the other in strength. First Esau will subjugate the whole world, but in the end Jacob will rule over all. The older of the two will serve the younger, provided this one is pure of heart, otherwise the younger will be enslaved by the older."
The circumstances connected with the birth of her twin sons were as remarkable as those during the period of Rebekah's pregnancy. Esau was the first to see the light, and with him all impurity came from the womb; Jacob was born clean and sweet of body. Esau was brought forth with hair, beard, and teeth, both front and back, and he was blood-red, a sign of his future sanguinary nature. On account of his ruddy appearance he remained uncircumcised. Isaac, his father, feared that it was due to poor circulation of the blood, and he hesitated to perform the circumcision. He decided to wait until Esau should attain his thirteenth year, the age at which Ishmael had received the sign of the covenant. But when Esau grew up, he refused to give heed to his father's wish, and so he was left uncircumcised. The opposite of his brother in this as in all respects, Jacob was born with the sign of the covenant upon his body, a rare distinction. But Esau also bore a mark upon him at birth, the figure of a serpent, the symbol of all that is wicked and hated of God.
The names conferred upon the brothers are pregnant with meaning. The older was called Esau, because he was 'Asui, fully developed when he was born, and the name of the younger was given to him by God, to point to some important events in the future of Israel by the numerical value of each letter. The first letter in Ya'akob, Yod, with the value of ten, stands for the decalogue; the second, 'Ayin, equal to seventy, for the seventy elders, the leaders of Israel; the third, Kof, a hundred, for the Temple, a hundred ells in height; and the last, Bet, for the two tables of stone.