Isaac was highly honored by God in being made inheritor of the promises through which the world was to be blessed; yet when he was forty years of age he submitted to his father's judgment in appointing his experience, God-fearing servant to choose a wife for him. And the result of that marriage, as presented in the Scriptures, is a tender and beautiful picture of domestic happiness: "Isaac brought her into his mother Sarah's tent, and took Rebekah, and she became his wife; and he loved her: and Isaac was comforted after his mother's death."

Den undervisning Abraham havde givet Ismael i barndommen, havde ikke været uden virkning, men Ismaels hustruers indflydelse resulterede i, at afguderiet blev indført i hans familie. Adskillelsen fra faderen og bitterhed fremkaldt af splid og kiv i et hjem, hvor Gud ikke blev elsket og frygtet, bevirkede, at Ismael kastede sig ud i en ørkenhøvdings vilde, omstrejfende liv - hans "hånd er mod alle, og alles hånd mod ham". 1. Mos. 16, 12. På sine gamle dage angrede han sit onde levned og vendte tilbage til sin faders Gud; men det onde havde sat sit præg på hans efterkommeres karakter. Det mægtige folk, der nedstammede fra ham, var et omflakkende, hedensk folk der bestandig var til gene og plage for Isaks efterkommere.