Matthew Henry Commentary Genesis 27:1-5

"And it came to pass, that when Isaac was old, and his eyes were dim, so that he could not see, he called Esau his elder son, and said unto him, My son. And he said unto him, Here am I. And he said, Behold now, I am old, I know not the day of my death. Now therefore take, I pray thee, thy weapons, thy quiver and thy bow, and go out to the field, and take me venison. And make me savory food, such as I love, and bring it to me, that I may eat. That my soul may bless thee before I die. And Rebekah heard when Isaac spake to Esau his son. And Esau went to the field to hunt for venison, and to bring it." — Genesis 27:1-5 (ASV)

The promises of the Messiah, and of the land of Canaan, had come down to Isaac. Isaac was now about 135 years of age, and his sons were about 75. Not duly considering the Divine word concerning his two sons (that the elder should serve the younger), he resolved to confer all the honor and power contained in the promise upon Esau, his eldest son. We are very apt to make decisions based on our own reason rather than on Divine revelation, and thus often go astray.