Even before they were born, Jacob and Esau struggled in the womb. They were destined, it seems, to be eternal adversaries. Not only were they different in character and appearance, they also held different places in their parents’ affections: “The boys grew up, and Esau became a skillful hunter, a man of the open country, while Jacob was a quiet man, staying among the tents. Isaac, who had a taste for wild game, loved Esau, but Rebecca loved Jacob” (Genesis 25:27-28).
We know why Rebecca loved Jacob. Before the twins were born, the pains Rebecca felt were so great that “she went to inquire of the Lord.” This is what she was told: “Two nations are in your womb, and two peoples from within you will be separated; one people will be stronger than the other, and the older will serve the younger” (Genesis 25:23).
It seemed as if G-d were saying that the younger would prevail and carry forward the burden of history, so it was the younger, Jacob, whom she loved.
But why, in that case, did Isaac love Esau? Did he not know about Rebecca’s oracle? Had she not told him about it? Besides, did he not know that Esau was wild and impetuous? Can we really take literally the proposition that Isaac loved Esau because “he had a taste for wild game,” as if his affections were determined by his stomach, by the fact that his elder son brought him food he loved? Surely not, when the very future of the covenant was at stake.
The classic answer, given by Rashi, listens closely to the literal text. Esau, says the Torah, “knew how to trap [yodeia tzayid].” Isaac loved him “because entrapment was in his mouth [ki tzayid befiv].” Esau, says Rashi, trapped Isaac by his mouth. Here is Rashi’s comment on the phrase “knew how to trap”: “He knew how to trap and deceive his father with his mouth. He would ask him, “Father, how should one tithe salt and straw?” Consequently his father believed him to be strict in observing the commands” (Rashi to 25:27).
Esau knew full well that salt and straw do not require tithes, but he asked so as to give the impression that he was strictly religious. And here it is Rashi’s comment on the phrase that Isaac loved him “because entrapment was in his mouth”: “The midrashic explanation is that there was entrapment in the mouth of Esau, who trapped his father and deceived him by his words” (Rashi to 25: 28).
The Maggid of Dubnow adds a perceptive comment as to why Isaac, but not Rebecca, was deceived. Rebecca grew up with the wily Laban. She knew deception when she saw it. Isaac, by contrast, had grown up with Abraham and Sarah. He only knew total honesty and was thus easily deceived. (Bertrand Russell once commented on the philosopher G. E. Moore, that he only once heard Moore tell a lie, when he asked Moore if he had ever told a lie, and Moore replied, “Yes”).
So the classic answer is that Isaac loved Esau because he simply did not know who or what Esau was. But there is another possible answer: that Isaac loved Esau precisely because he did know what Esau was.
In the early 20th century someone brought to the great Rabbi Avraham Yitzhak Kook, first Ashkenazi Chief Rabbi of pre-state Israel, the following dilemma: He had given his son a good Jewish education. He had always kept the commands at home. Now, however, the son had drifted far from Judaism. He no longer kept the commandments. He did not even identify as a Jew. What should the father do?