Vayishlach, 32:33. Gid Hanosheh.

Why is the Gid Hanosheh ossur? Imi Morosi Shlita asked me, how does the story of Yakov and the Maloch and the injury to Yakov’s gid hanosheh explain “al kein lo yochlu.” Where’s the explanation? Yes, there’s a story of the injury to the gid hanosheh, but why shouldn’t we eat it? Maybe we should davka eat it to remember the story! Maybe we should wear it on our arm, like tefillin? Or nail it to the doorpost?
1. The Zohar here says that the 365 lavin correspond to the 365 days of the year and the the 365 gidim of the human body, and to 365 malochim. Of course, the lav of Gid Hanosheh corresponds to the Gid Hanosheh, and the day it corresponds to is Tisha Ba’av, and the maloch is Samo’eil, who has shlitoh over the day of Tisha Ba’av. The Chasam Sofer in Parshas Devarim says that Yaakov's fight with the Sar shel Eisav took place on Tisha Ba'av.
2. The Chinuch, in #3, says that the Gid Hanosheh symbolizes the difficulties of the galus and the damage caused by the Sar shel Eisov and Eisov himself, and the ultimate healing of the geulah.
3. The Netziv says that Yakov was taught that once he had beaten the Maloch, he shouldn’t have continued fighting with him. This is a lesson that if a person is a nirdof, he should, of course, defend himself, but once he has saved himslef, he should not continue fighting. The symbol of the gid is that it is hard, like an erez, and a person should be soft like a koneh, not hard like an erez, even to his enemies, as the Gemorah in Taynis third perek says.
4. The sefer “Shollol Rov” brings that Reb Shimon Shkop said that this mitzvah teaches that when our mesorah and kefira are joined in battle, there is usually resulting injury to us.
5. I happened to see a review of a printing of a sefer called “Mei’ah She’arim” (Ofeq Institute, Jerusalem, 2001) in the Jewish Action magazine. This is a sefer on the din of Kibud Av written by R’ Eliyahu Capsali, a 16th Century Cretan Rov. He is quoted in the review as saying that the issur of gid hanosheh was a punishment for Yaakov’s children for having left him alone and vulnerable at Nachal Yabok. Also said by the Daas Zkainim and the Chizkuni.
6. The Chidushei Hage’onim in the Ein Yakov in Sanhedrin 110 brings from the Ein Eliahu: the Maloch of Eisov had no shlita over Yakov because he was clean from the sin of gezel— as it says, that he was makpid on his pachim ketanim, showing a kepeidah in his property, because he was nizhor from gezel. So the Maloch, seeing “ki lo yuchal lo,” hurt him through his children, symbolized by the kaf hayorech, because the children were not as nizhor from gezel. Therefore, we don’t eat the Gid Hanosheh which is a symbol of the power of Eisav over us caused by our imperfect care to avoid gezel. (It would seem that we should eat the Gid and be makpid on gezel— unless the pshat is that it is supposed to be a mussar haskeil, a reminder, to be careful. If so, it would help if the symbol was less obscure.)
7. The Ohr Hachayim says that since the gid was moved from its proper place by the Sar shel Eisov, it was nifgam and shouldn’t be eaten.
8. And let’s not forget the Sh'loh’s vort about the letters Choph and Phei, which symbolize the power of empathy and the power of speech.