The most famous appearance of these words is in Rashi's comment to Gen 33:4
There are dots above vayishakayhu. There is a difference of opinion concerning this matter in the Beraysa of the Sifre. There are those who explained these dots as saying that he did not kiss him wholeheartedly. R. Shimon b. Yochai said: "It is a known fact (halacha b'yaduah) that Esav hates Yaakov, but, his mercy was aroused at that moment and he kissed him with all of his heart."In this comment, Rashi is attempting to explain the dots which appear over the word "and he kissed him." (ie: vayishakayhu) One opinion says the kiss was not a real kiss, but a bite; therefore the word is dotted. Shimon Bar Yochai goes the other way, and says the kiss was real, but the dots are needed because everything we've seen in the narrative so far indicates that Esav hates his brother, and would sooner knee him in the crotch than kiss him. Were it not for the dots, everything we know about Esav would cause us to doubt the sincerity of the kiss.
The words Esav sonei le’Yakov, therefore, should be understood as a straightforward, statement of fact about the nature of Yakov's relationship with his brother; unfortunately they are not. Instead, the words have been used for centuries to explain, and even justify anti-Semitism. It has even made it impossible for some Jews to negotiate with gentiles in good faith. Why should we bother, these Jews reason, after all Esav sonei le’Yakov.
All of this has happened because Rashby chose to describe Esav's attitude toward Jacob as a "halacha b'yaduah."
Artscroll (Artscroll!!) translates these words as "known fact" and in the notes, the editor makes it clear that the subject of R’ Shimon’s observation is Yakov’s brother, not the nation (Edom) descended from him. Unfortunately, the average Jew on the street sees the words "halacha" and imagines some imperishable rule of life has been announced. Perhaps this is what the words halacha suggests in our day; in Rashby's time, though it meant something less, something like "rule" or "fact" or "opinion."
The known opinion Rashby is citing is that Esav, the person, hated Yakov, the person. No information about the future is suggested or implied. For if Rashby had intended to give us information about the nations these two brothers would produce, he would have used the words the Torah uses whenever it speaks of those nations, and instead he would have said Edom sonei l'Yisroel.
GAME SET MATCH
What follows is the midrash in context, supplied elsewhere by Elder:
:דבר אחר לך לקראת משה המדברה, זש"ה מי יתנך כאח לי (שה"ש ח, ישראל אומרין לפני הקדוש ברוך הוא מי יתנך כאח לי, את מוצא כל האחים שונאים זה לזה קין שונא להבל שנ' (בראשית ד ויקם קין אל הבל אחיו וגו', ישמעאל שונא ליצחק שנאמר ותרא שרה את בן הגר המצרית וגו' (שם כא ואין מצחק אלא שבקש להרגו שנאמר יקומו נא הנערים ויצחקו (שמואל ב ב), עשו שונא ליעקב שנאמר ויאמר עשו בלבו וגו' (בראשית כו, השבטים שנאו ליוסף שנאמר וישנאו אותו (שם לז
From here its clear, obvious and irrefutable that the speaker's subject is individuals, not nations.