Our Gemara on amud aleph discusses the legal implications where one person derives benefit from someone else, but there was no loss incurred. This is not to say that it is permitted to squat on someone’s property, but the Gemara considers that in situations where there is zero loss and wear and tear, there can be no financial liability on the beneficiary. 

Rav Shlomo Kluger (Chokhmas HaTorah, Toldos) uses this legal reasoning to explain Yaakov’s justification for stealing his father’s blessing from Esau.  When Yitschok learns that he gave the blessings to Yaakov who disguised himself as Esau, he tells Esau (Bereishis 27:35):

וַיֹּ֕אמֶר בָּ֥א אָחִ֖יךָ בְּמִרְמָ֑ה וַיִּקַּ֖ח בִּרְכָתֶֽךָ׃

But he answered, “Your brother came with guile and took away your blessing.”

The Midrash Rabbah (67:4) interprets the word “guile” as “Talmudic reasoning”. Meaning, Yaakov used some halakhic argument to justify his appropriating the blessings for himself. What was the legal argument? Rav Kluger says, the Midrash (65:13) also tells us that Esau was not particularly respectful of his father’s religious convictions. If he did not find a kosher animal to slaughter, he would grab whatever he could trap. The Midrash derives this from the verbose description of Esau’s (27:5), “לצוד ציד להביא” “to trap game and to bring”, implying he will do whatever it takes to bring back something. Yaakov reasoned, “Esau will probably bring something non-kosher and that meal could not have possibly brought Father to a state of divine inspiration. Though I gained, Esau did not lose out, as he never would have received the blessings anyhow. Therefore, I have no further liabilities to Esau.”

However, I wonder how Rav Kluger fits his peshat in with the clearly stated verse (Bereishis 25:31) that indicates Yaakov bought the firstborn rights fair and square? What legal argument is more powerful than that? We must answer that there were two different legal issues. True, Yaakov purchased the rights to the firstborn but perhaps Essu would argue that the blessing was essentially a non-transferable right? Perhaps only Yitschok gets to decide who receives a blessing and no one has the right to sell it?

To this Yaakov would answer, even if Father attempted to give it to you, you would not have gotten it, because you would have fed him non-kosher food. This also will answer another question, how did Yaakov know for sure that Esau would bring non-kosher food? Even the Midrash says that if he was fortunate enough to trap a Kosher animal, he would have brought that. Using our current reasoning, all Yaakov needs to do is create reasonable doubt because this is a post facto demand for compensation. If Esau cannot prove that he lost out, because he may never have been able to get the blessings anyway, then he cannot extract payment from Yaakov.

Reflecting on this story, it does make you wonder what is the divine purpose that our very identity and ancestral origin story has to be rife with intrigue and underhanded, indirect machinations to receive our birthright? We are rightfully entitled to it, why did God make it so complicated with so many consequences for Yaakov’s life and future history?

I believe the main function of this is to create humility. Being the chosen people could easily lead to being “the only people”, and regard everyone else as less than Human. (It is certainly is how Jews have been treated at times throughout history.) Therefore, to humble us, we don’t get to feel like we’re absolutely entitled. And, perhaps, even the other nations of the world don’t have to feel utterly dejected. They also were contenders, and in some fundamental way can still be contenders in God‘s plan.

The idea that leaders must be humbled by circumstances and their past is taught in regard to the Davidic dynasty In Gemara Yoma (22b):

אָמַר רַב יְהוּדָה אָמַר שְׁמוּאֵל: מִפְּנֵי מָה לֹא נִמְשְׁכָה מַלְכוּת בֵּית שָׁאוּל — מִפְּנֵי שֶׁלֹּא הָיָה בּוֹ שׁוּם דּוֹפִי, דְּאָמַר רַבִּי יוֹחָנָן מִשּׁוּם רַבִּי שִׁמְעוֹן בֶּן יְהוֹצָדָק: אֵין מַעֲמִידִין פַּרְנָס עַל הַצִּיבּוּר אֶלָּא אִם כֵּן קוּפָּה שֶׁל שְׁרָצִים תְּלוּיָה לוֹ מֵאֲחוֹרָיו. שֶׁאִם תָּזוּחַ דַּעְתּוֹ עָלָיו אוֹמְרִין לוֹ: חֲזוֹר לַאֲחוֹרֶיךָ.

Rav Yehuda said that Shmuel said: Why did the kingship of the house of Saul not continue on to succeeding generations? It is because there was no flaw in his ancestry; he was of impeccable lineage. As Rabbi Yoḥanan said in the name of Rabbi Shimon ben Yehotzadak: One appoints a leader over the community only if he has a box full of creeping animals hanging behind him, i.e., he has something inappropriate in his ancestry that preceded him. Why is that? It is so that if he exhibits a haughty attitude toward the community, one can say to him: Turn and look behind you and be reminded of your humble roots. This is why David’s kingdom lasted while Saul’s did not, as David descended from a family with problematic ancestry, namely Tamar (see Genesis, chapter 38) and Ruth the Moabite (see Ruth 4:18–22).

The Jewish monarchy did not have checks and balances that we would have in a modern democracy, but nevertheless there were divine checks and balances.