Today’s gem comes in a long discussion (pasted below) about why the Mishnah says we would burn leftover sinews, when, in general, sinews are permitted to be eaten? Eventually, Rabbis Hisda, Yehudah, Ika bar Hanina, Ashi, and Ravina conclude that this is talking about the sciatic nerve.
The prohibition on the sciatic nerve comes from Genesis 32:33 after Jacob wrestles with the angel and wrenches his hip: “Therefore the Israelites do not eat the displaced nerve (gid ha-nasheh) on the hip joint to this very day.”
But which hip? And which part of the nerve is forbidden?
Why I find this at all interesting, is that we have here an example of very smart men who set the rules and can figure out exactly how to walk the line second guessing themselves. It sends the message: when in doubt, err on the side of caution.
And that is a gem indeed.
Here is the discussion:
Rav Ḥisda said: The mishna’s mention of sinews is necessary only for the sciatic nerve, in accordance with the opinion of Rabbi Yehuda.
As it was taught in a baraita that Rabbi Yehuda said: The prohibition to eat the sciatic nerve according to Torah law applies only to the sciatic nerve in one of the animal’s thighs, and not to both, and logic dictates that it is the right thigh. However, since there is no absolute proof that this is correct, the sciatic nerve must be removed from both sides. Although in theory the forbidden sciatic nerve may be discarded and the permitted one may be eaten, since there is uncertainty as to which one is permitted, neither of them may be eaten. Both must be burned.
The Gemara asks: Shall we then conclude that Rabbi Yehuda was uncertain about which sciatic nerve is forbidden? The Sages were unsure whether Rabbi Yehuda was absolutely convinced that it is the sciatic nerve from the right side that is forbidden, or if he was saying that this would seem likely to be the case, but he was not certain. As, if it were clear to him that it is the sciatic nerve from the right thigh that is forbidden, the proper procedure would be different: The one that is permitted we should eat, and the one that is forbidden we should discard. Why should he require burning?
Rav Ika bar Ḥinnana said, in response to this attempted proof: The mishna addresses a case where the two sciatic nerves were known, but in the end became mixed together. In other words, at first it was known which was the forbidden right nerve and which was the permitted left nerve. However, they were then mixed together and can no longer be identified. Therefore, due to the uncertainty, they must both be burned.
Rav Ashi said: The mishna’s ruling that the sinews must be burned is necessary only with regard to the fat of the sciatic nerve, as it was taught in a baraita: The fat around the sciatic nerve is permitted according to Torah law, but the Jewish people are holy and treat it as forbidden. Since it is permitted according to Torah law, it has the status of meat and may not be simply discarded. However, since the Jewish people treat it as forbidden, they do not eat it even from the Paschal lamb. Therefore, it is left until after the time when the meat may be eaten and burned in accordance with the general halakha of leftover.
Ravina said: This discussion pertains to the outer nerve, and it is in accordance with that which Rav Yehuda said that Shmuel said, as Rav Yehuda said that Shmuel said: There are two sinews in the sciatic nerve: The inner sinew that is next to the bone is forbidden according to Torah law, and one is liable to be flogged for eating it. The outer sinew that is next to the meat is forbidden by rabbinic law, and therefore one is not liable to be flogged for eating it. Since the outer sinew is permitted according to Torah law, it attains the status of leftover when it is not eaten.
