Genesis 32:33 a law or a custom?

Question

It is mentioned in The Tanach that Jacob fought with an 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)

Some people claim that without the Oral Torah, all that we can get from the story of Jacob in Genesis 32, is that Israelites avoiding the gid hanasheh was merely a custom, they just decided to do so, God never issued a law in the tanakh, regarding consuming Gid hanasheh.

is their reading right?

Another question : Was the Rabbis'Halakha regarding the prohibition of gid hanasheh, should be equally respected, and treated as inspired from God, as all other laws with regard to non-sacred animals, etc that are mentioned in the Tanakh? or may be their prohibition of gid hanasheh was an error that has no basis on the tanakh.

Thank you.

Answer 1

Some people claim that without the Oral Torah, all that we can get
from the story of Jacob in Genesis 32, is that Israelites avoiding the
gid hanasheh was merely a custom, **they just decided to do so, G-d
never issued a law in the tanakh**, regarding consuming Gid hanasheh.

Is that so? Let's have a look in Bereishis 32:33, the posuk that deals with this. It clearly states:

Therefore the children of Yisra᾽el eat not of the sinew of the vein, which is upon the hollow of the thigh, to this day: because he touched the hollow of Ya῾aqov’s thigh in the sinew of the vein.

Sforno, a commentator, writes:

על כן לא יאכלו בני ישראל, in order to ensure that the damage inflicted to Yaakov’s offspring as predicted by the angel should be kept to a minimum as long as they remind themselves of the symbolic meaning of that injury suffered by Yaakov during his nocturnal encounter with this angel.

We do not eat it, and according to Sforno, this is to uphold the symbolic meaning to it. But that does not mean that it was given by our Sages, and has no foundation in the Torah, because the posuk clearly says it.

The Rambam however, writes that biblically only the gid is forbidden to be eaten:

According to Scriptural Law, only [the gid] on the hip socket is forbidden

Regarding the remainder, Rambam writes:

The remainder of the gid which is above the socket or below the socket - and similarly, the fat which is on the gid - are forbidden only according to Rabbinic decree.