Yesterday we began discussing the prohibition on eating the sciatic nerve of kosher animals, and entered a discussion about whether it is prohibited on both sides or just one. That discussion continues today, diving much deeper into the biblical story that the Torah cites as the origin for the law.
Recall that Genesis 32 begins with Jacob, who has journeyed back to his ancestral land and is preparing himself for a tense reunion with his estranged elder twin Esau, whom he swindled out of their father’s blessing and the birthright. On the night before they meet, a man, perhaps an angel, attacks Jacob and the two wrestle all night. In the final stages of their competition, the angel pulls Jacob’s hip out of its socket. Despite his injury, Jacob holds the angel down and demands a blessing — which is how he receives a new name, Israel. At dawn, the angel retreats and Jacob limps away, after which the narrator reports:
“That is why the children of Israel to this day do not eat the thigh muscle that is on the socket of the hip, since Jacob’s hip socket was wrenched at the thigh muscle” (Genesis 32:33).
This terse story raises many unanswered questions: Who is the strange assailant? And why did he attack? What is the meaning of the injury that leaves Jacob limping away from his victory? Why does this incident lead to a law not to eat the sciatic nerve?
Today’s daf begins on a more mundane note, using the verse to help locate whether the forbidden sciatic nerve is on the right or left side. There seems to be a general agreement that if it’s only one side, it must be the right. But there are many explanations for this identification.
What is the reason (for the right side)? Rava said that it is because the verse states: “the thigh” (Genesis 32:33). This means the most important thigh.
Because the story says “the thigh,” reasons Rava, it means only one side is forbidden, and further it must be the stronger leg, usually the right side.
Then we encounter a second explanation:
Rabbi Yehoshua ben Levi said the verse states: “as he wrestled with him” (Genesis 32:26). The angel grappled with Jacob like a man who hugs another, and his hand reaches to the spoon of the right thigh of the other.
Rabbi Yehoshua ben Levi describes two people wrestling, one reaching his hand around his opponent’s back to their right thigh. Interestingly, this image of wrestling includes the word to “hug,” hinting at the complicated relationship between Jacob and his angelic opponent.
They embrace as they struggle, perhaps as brothers who both love and fight one another would.
Two more rabbis present arguments that the prohibition applies to the right side:
Rabbi Shmuel bar Nahmani says: The angel appeared to him as a gentile, as the master said: A Jew who is joined by a gentile on the road should position the gentile to his right.
An unnamed sage (“the master”) warns that you should always keep gentiles, who are outside the community and therefore suspicious, to your right. This is presumably so that your stronger right hand is available for protection. Rabbi Shmuel bar Nahmani asserts this is what Jacob did, and when the angel reached for him he had access to his right thigh.
The final argument is quite the opposite.
Rav Shmuel bar Aha said before Rav Pappa in the name of Rava bar Ulla that the angel appeared to Jacob as a Torah scholar, as the master said: One who walks to the right of his teacher is an ignoramus.
To show respect, the polite thing to do in rabbinic times was to walk on the left side of one’s teacher, a visual reminder of each person’s rank. According to Rav Shmuel bar Aha, Jacob saw the angel not as an enemy but as a sage, and politely positioned himself on the angel’s left, leaving his right side unprotected — which is how we know this is the damaged hip.
While all four sages on today’s daf are in agreement that the forbidden sciatic nerve is on the right side, they disagree about why. The arguments that engage with the story are particularly interesting. Was Jacob wrestling with his brother? With an enemy? With a teacher? And what do each of these figures, if they are the opponent, represent? What does this mean for Jacob’s nocturnal struggle? This halakhic sugya does not select a single right answer. While there is agreement that if only one sciatic nerve is forbidden, it’s the one on the right, there is a proliferation of hypotheses about the deeper meaning of Jacob’s mysterious encounter.
Read all of Chullin 91 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on July 30, 2026. If you are interested in receiving the newsletter, sign up here.
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