Genesis 28:1-4

"And Isaac called Jacob, and blessed him, and charged him, and said unto him, Thou shalt not take a wife of the daughters of Canaan. Arise, go to Paddan-aram, to the house of Bethuel thy mother's brother; and take thee a wife from thence of the daughters of Laban thy mother's brother. And God Almighty bless thee, and make thee fruitful, and multiply thee, that thou mayest be a company of peoples; and give the blessing of Abraham, to thee, and to thy seed with thee; that thou mayest inherit the land of thy sojournings, which God gave unto Abraham."

The difference between this blessing and the one that Isaac mistakenly conferred upon Jacob earlier is rather striking. In the first, there was no mention of the Abrahamic promise, but here Isaac apparently made an effort to go all the way in conferring the covenant blessing. But even in this there could have been a deficiency, a lack supplied by God Himself in the vision that came as a sequel, that being the fact that "all the families of the earth" would be blessed in his seed. Nevertheless, even as it stood, the blessing seemed to convey the impression that Isaac had repented of his sinful effort to convey the birthright to Esau.

"Thou shalt not take a wife of the daughters of Canaan ..." These are almost the same words spoken by Abraham to the servant who was sent to procure Rebekah for Isaac. And one can only marvel that Isaac had avoided and neglected this task as long as he had. The usual calculation for the age of Jacob at this time Isaiah 77 years, although another method of calculating his age makes it about 57.[1] If the first is correct, then Ishmael had been dead fourteen years when Isaac commanded Jacob to go to the house of Bethuel. If the second calculation is allowed, Ishmael still lived and would not have died until six years later. The statement that "Esau went unto Ishmael" (Genesis 28:9), inferring that Ishmael was alive at the time of the events of this chapter, definitely favors the lower calculations of 57 for the age of Jacob. The Bible here says nothing whatever about anyone's age, and human deductions are subject to all kinds of errors.