Gid hanasheh

The Torah (Genesis 32) recounts that Jacob fought with an angel (according to Rashi, this was Esau's guardian angel) who could not beat him. At the end of the fight, the angel strikes a nerve in Jacob's leg, causing him to limp. The verse then states: "Therefore the Israelites do not eat the displaced nerve (gid ha-nasheh) on the hip joint to this very day." (Genesis 32:33)

The Zohar explains that the thigh is the root location of sexual desire. While most evil urges can be overcome, there is one lust that is so strong that it overpowers even great men - the gid ha-nasheh. Its very name nasheh means “forgetting” (cf. Genesis 41:51), because once this desire has been aroused, we forget all rational thinking and moral scruples. The only way to win this battle is to completely distance ourselves from it. For this reason, the gid ha-nasheh is not eaten at all but entirely avoided.[1]

Rabbi Abraham Isaac Kook explained that the prohibition of eating gid ha-nasheh demonstrates that, while we may need to slaughter animals for our physical needs, we do not seek to subjugate others, whether man or beast. For this reason, we make great efforts to avoid eating the sciatic nerve - a nerve that allows the body to stand upright.[2][3]

The removal of the gid hanasheh and chelev (forbidden fats) is called nikkur. Since it is labor-intensive to remove all the forbidden parts of the hindquarters of an animal, the entire hindquarters are usually sold to the non-kosher market outside of Israel and a few other markets with sufficient Jewish populations to justify the expense.

In the situation of a ben pekuah the nerve is permitted to be eaten. This potential reduction in expense is part of a project that began in Melbourne to create a herd of ben pekuah animals.[4][5]

• Sciatic nerve — non-Hebrew terminology