According to Midrash Tanchuma, Eisav tricked Yitzchak into loving him. The Midrash goes on to elaborate that Eisav would ask his father things that would make him look righteous, such as whether one needs to give tithes from salt.
There are two ways that a person can be deceitful. A person can have an accurate sense of self but try to fool others by not showing his or her true colors. Alternatively, a person can take the deceit so far that they even deceive themselves. In this case it is much more difficult to spot the deception as the lines between truth and lies have been blurred. Eisav is a person who began to believe his own lies. Midrash Rabba teaches that Eisav is symbolized by the pig. A pig has split hooves but does not chew its cud. The pig always lays down with its hooves outstretched for everyone to see, as if to say, “look at me, I’m kosher.” Eisav’s ability to deceive even himself was what caused Yitzchak to be deceived as well.
Alternatively, one can view Eisav as being sincere, yet his flaw was that he was terribly inconsistent. Our Rabbis teach that on the day that Eisav sold the birthright to Yaakov he violated five serious sins, among them “Kafar b’Ikar” denying the very existence of G-d. And yet this does not prevent Yaakov from demanding that Eisav swear that his deal to buy the birthright is binding. It seems peculiar that Yaakov would accept Eisav’s oath in light of the grave sins that Eisav had recently committed. The Altar from Slobodka explains that Eisav’s problem was that he lacked any shred of consistency. He was capable of committing the worst of sins one moment, and then taking an oath the next and sincerely meaning what he said. This approach can shed a new light on a passage from the Talmud Yerushalmi in Nedarim:
“In the future, Eisav will wrap himself in a tallis and sit together with the righteous in Gan Eden. But G-d will yell at him and kick him out.”
The standard interpretation of this passage is that Eisav is acting like a faker. However Rabbi Boruch Sorotzkin explains that this passage alludes to Eisav’s lack of consistency. During his lifetime at times he was deserving of being rewarded among the righteous. However, G-d ultimately kicks him out because he lacked consistency to maintain that degree of merit.
The Gemara in Sota tells us that Eisav’s head was buried together with the righteous in Ma’arat Hamachpela in Chevron. This is because Eisav had good intentions, but he lacked the consistency to follow through on those plans. It could also be that whenever it came time to actualize those good intentions, Eisav deceived himself that those efforts were not necessary; and then he deceived others into thinking that he had in fact put in the effort.
Life is a marathon, not a sprint. In order to achieve our goals we must try our best to be consistent- in our values and in our efforts. We must also be honest with others, and especially ourselves, when we evaluate our values, our efforts and our achievements.