Esau and Jacob were very different voice. Esau was a hunter, a man of the fields. Jacob was a scholar, a man of the tents. Their parents also differed on their approach to the boys: "Isaac loved Esau, for his hunting was in his mouth. And Rebekah loved Jacob." Later in life, when Isaac came to give the blessing of the firstborn to Esau, Rebekah engineered Jacobs receiving that blessing through deception. It is this story that is the most edifying, so we shall look at it in great depth.
Isaac told Esau to go out into the fields and hunt for him a feast. Thereupon, Isaac would give the blessing to Esau. Esau duly went out to do his father's bidding, while Rebekah overheard the entire exchange. She called Jacob in quickly, encouraged him to pose as Esau and receive the blessing. This could work because Isaac had grown blind at this point in his life.
The trick works, Isaac is fooled and gives the blessing to Jacob. Just as he leaves, Esau arrives with his feast. When he hears his father tell him that someone else had come and received the blessing, Esau is distraught. He begs his father for some blessing, any blessing. After Isaac gives him a secondary blessing, he leaves his father's tent with a promise upon his lips: to kill his brother Jacob after his father Isaac has departed.
Along with the sale of Joseph, this is one of the tragic tales of the book of Genesis. I wish to understand one thing. Why did Isaac require Esau to bring him hunted meat in order to bless him? Was physical enjoyment so important to Isaac? That is certainly impossible to believe. And yet, as in the quote above, we know that Isaac's love for Esau was due to his "hunting in his mouth." What was the significance of this?
Now, Esau was, according to our sages, an evil person. He stole, he killed. We see this in his desire to kill his brother after his father passes away. Why, then, does Isaac wish to bestow the blessing upon him? Why does Rebekah have to conspire with Jacob to get the blessing for him, who truly deserves it? What was Isaac thinking?
I had an intriguing thought on this: perhaps Isaac knew all along that Esau was not nearly as righteous as Jacob, and that he did commit violent acts. Perhaps he also saw that Esau had potential, that he could repent and become a great person. I know people who were completely out of control in their high school years, who became very serious and respected teachers of Torah. I wonder if Isaac was not trying to nudge Esau in that direction.
Very often, responsibility changes in person. The incident early in their lives when Jacob got Esau to sell him his birthright in exchange for some lentil soup may have been what set the tragedy of Esau in motion. Perhaps had Esau kept the birthright, and the responsibility of leadership that comes with it, he might have developed into a different man. As it was, after Jacob had procured it, Esau walked away "and despised the birthright."
According to a rabbinical source, when Isaac sent Esau to get the hunted meat for him, he included a proviso that the meat not be stolen. Firstly, this interpretation indicates that Isaac was aware of Esau's behavior. Secondly, it seems to me that this might be a test. Isaac knew that Esau excelled in honoring him, and this gave him great satisfaction and hope. Perhaps, even if in the outside world he misbehaved, is respect and honor for his father might transform him. It might indicate that there is strong good within him. Thus, Isaac gave him a simple instruction: nothing stolen.
And when he returned, he returned with stolen goods. The blind Isaac senses the opening of purgatory the moment Esau enters. When Jacob had entered, Isaac had smelled the aroma of the Garden of Eden. In the Garden of Eden, there was no theft. Everything belonged to Adam and Eve. But purgatory is for sinners. Thus, Isaac knew that Esau had failed the test, and he then reaffirmed the blessing for Jacob. He had hoped to reform his older son, but realized it was not happening.
I wish to add a new twist to this whole story. Our sages tell us that there are two types of love: 1. A love which is dependent upon a physical factor. 2. A love which is not dependent upon anything physical at all.
The first half of love lasts only as long as that physical factor does. Then it can turn into hate or indifference. The second type of love will last forever. I believe that Isaac and Rebekah represent these two types of love. Isaac loved Esau for a reason, because of the "hunting that was in his mouth," because of his deep respect for his father. An alternative translation of the phrase, "because of the hunting that was in his mouth," could be "as long as the hunting was in his mouth." The word "ki" can mean "because" and it can also mean "during" or "as long as."
I believe that Isaac loved Esau for deep psychological reasons, although he knew intellectually that it was not a well-placed love. Nonetheless, he sought out physical reasons, signs of hope, indications of a goodness that was not there, to justify the love. And, perhaps with the right influence, Esau might have been reformed. Had Jacob not bought his birthright, had the blessing been delivered as planned, maybe Esau would've stepped up to the plate. Much later, when Jacob is returning to the land of Israel, he hides his daughter Dina, lest Esau desire for a wife. Some rabbis are critical of this, claiming that she would have succeeded in reforming him. It is speculation, although Esau did moderate as he aged.
Rebecca, on the other hand, loved Jacob unconditionally. The Torah as no criteria that caused it. That is the difference. A strong emotion can be an indication of a true course of action, as long as the emotion is not accompanied by nagging doubts, and as long as it does not require any justification. Rebecca's internal sense was that Jacob was thoroughly good, and Esau was not. Isaac wanted to loved Esau and favor him, and had to justify it by his remarkable honoring of his father. That wasn't enough.
So be careful when the emotions are not pure, when you feel you need to justify them to choose a course of action. Many women married men who were abusive in nature by justifying their love and grasping at straws to believe that they are not the monsters they are. On the other hand, a true emotion, with no doubts and no need of justification, is a true indication of where the heart is and should be taken seriously.