Yaakov simmered a stew, and Eisav came from the field, and he was exhausted. That's what the Torah says (in writing). Rashi tells us the details. This episode happened on the day that Avraham Avinu died and that Eisav, who until that day, had nor veered from the proper path... committed a murder.
The gemara in Bava Batra tells us that on that very day, Eisav committed five series sins - a rape, a murder, denial of the Revival of the Dead, denial of the essence of Judaism, and belittled the B'CHORA and what it stands for. Furthermore, the gemara matches words in the pasuk in To-l'dot to the same words in other p'sukim to "support" these details. SADEH, a field (or, perhaps, a forrest) is associated with rape - this based on p'sukim elsewhere in the Torah. And that AYEIF, exhausted, is associated with murder - this also based on p'sukim elsewhere. The other sins are matches to certain phrases used by Eisav.
Wait a minute! SADEH can also mean - and usually does mean - a field. At the end of Chayei Sara, Yitzchak Avinu goes into the field towards evening to commune with G-d - to daven the first Mincha, so to speak. What deep meaning does Yitzchak's having gone into the SADEH have? No connotation and certainly no negative association. Why could it not have been a regular field from which Eisav was coming. Why could not Eisav have been just simply very tired? Why attribute five very serious sins to "dear uncle Eisav" who spent a tiring number of hours (or days) working hard and hunting in the field. Why do we brand Eisav a murderer, a rapist, and a denier of fundamental aspects of our belief.
Especially when it doesn't say those things in the Torah. The Torah does not say that Eisav was a wicked individual.
Ah, but it DOES say those things. Not in the written words of the Torah, but in the other part of the Torah, so to speak - in Torah sheb'al peh, the Oral Torah, the Oral Law, the Oral Tradition. The Torah does not write that Eisav was wicked, but it most definitely SAYS so.
And that's the point of this D'var Torah. Our Sages were not doing a hatchet job on Eisav. They were telling us "how it is" - which they didn't make up; they received it as a Tradition handed down from generation to generation.
We see this same idea in halachic contexts - not just drash of a story.
Ask anyone to take put the tip of his finger right between his eyes. It is almost certain that the person's fingertip will end up on the bridge of his nose. But when the Torah commands us to put the T'filin (yes, the singular of T'filin is T'fila, but that word would puzzle some readers more than this word will bother the purist among the readership) of the head, BEIN EINECHA, between your eyes, it did not mean to put it on the bridge of the nose, literally between the eyes. Put it there and the mitzva is not fulfilled. At all. The Written Word says BEIN EINECHA and the Oral Law explains what that means and teaches us where to position the Shel Rosh.
Make your own definition of BEIN EINECHA and you're not doing the mitzva properly.
Similarly, with words that have exclusive and inclusive meanings. YOM can be a 24-hour period or it can be daytime as opposed to nighttime. BEN can be son; it can also mean child. Only Torah Sheb'al Peh can tell us the correct meaning of many words of the Written Torah.
Think Eisav was an okay guy who was repeatedly deceived by his cunning brother - you'd be wrong, again.
There are so many examples of this idea in all aspects of the Torah. An eye for an eye does NOT mean that one loses his eye if he caused that kind of injury to another. But that's what it says in the Torah. No, that's the literal meaning of the words in the Written Torah. They cannot be understood without the Oral Law.
Why is it written in the Torah, an eye for an eye? Why does the Torah write that one shouldn't cook a baby goat in its mother's milk when it means for more than that? Why does the Torah write about keeping one's vow and doing everything that one says, when there is the halachic procedure of Hatarat Nedarim that allows one to have a vow voided - this not being written in the Torah at all.
There are answers to all of these questions - some are easy for us to understand and others that puzzle and mystify us. But we believe that the Written Word and Oral Law combine to show us what G-d wants of us.
And this does not mean that there is only one way to understand certain things we find in the Torah. In a couple of weeks we will read of the brief reunion of Yaakov and Eisav. And we will read of Eisav's kissing of Yaakov. And the word, and he kissed him, will be written in a Sefer Torah with dots above each letter, and our Sages will disagree on exactly what the Torah is trying to say to us.
And when differences of opinion exist in halachic contexts, we have the very important process of P'sak Halacha to teach us how to act. It's kind of complicated, but it is important for us to always remember the role of the Oral Law and of those who transmit it to us through the generations.
Back to the Written Word. The Torah is not silent or vague about Eisav's attitude and rejection of the birthright. The Torah says, VAYIVEZ EISAV ET HAB'CHORA - Eisav rejected and disparaged the Birthright. That and other phrases give the hints and links to the Oral Traditions. Also remember: 70 'faces' to the Torah. Commentaries have a variety of understandings about this parsha.