Genesis 25:20 Isaac was 40 years old when he took את־ Rebekah as a wife, the daughter of Bethuel, the Syrian of Padan-aram and the אחֹות sister to Laban the Syrian. C-MATS
Question: How old was Isaac when he married Rebekah? 40
Genesis 25:21 Isaac prayed to ליהוה for אשְׁתו his wife because she was barren: and יהוה listened to Isaac and Rebekah אשְׁתו his wife conceived. C-MATS
Question: Where did Isaac go to pray? Isaac and his wife rose up and went to the land of Mt. Moriah to pray there and to seek יהוה, and when they had reached that place Isaac stood up and prayed to יהוה on account of his wife. Isaac knew that he would have children because יהוה had promised Abraham his father that he would have many descendants, but he begged יהוה that the blessing be realized though the worthy woman who stood opposite him. (Jasher)
Question: Were all the matriarchs barren? The Maptriarchs Sarah, Rebekah, and Rachel were barren. The emergence of Israel is a miracle, for each new generation was a gift of יהוה to a mother who could not have given birth naturally. Their experience is a demonstration of the command that יהוה desires the prayers of the righteous (Yevamos 64a), whose pleas for Heavenly mercy and attempts at self-improvement show how human beings can raise themselves to spiritual heights. Chumash
Genesis 25:22 And the children struggled together within her; and she said, If it is going to be like this, why go on living? And she went to ask את־ יהוה. C-MATS
Question: Why were the children struggling within her womb and giving her pain in her pregnancy? The two sons would be two separate nations-Israel and Edom-with irreconcilable conflict between them. From the womb they are separated, this one to his wickedness, and this one to his innocence. They will not be equal in greatness; when one rises, the other will fall.