Rape of Dina.
This is the beginning of a new parsha. The verse 18-20 state: Yaakov came to Shechem
and he built there an altar and prayed to the G-d, G-d of Yisrael.
Rashi says: I am only giving the pshuto shel mikra.
People think that Rashi is interested in pshat. This is not so. In general he makes sure to explain the verses according to Chazal. Only occasionally he says that he is only giving the pshat.
Netziv says: Chas ve-Shalom that Yaakov would call himself G-d, but rather the verse means that he called himself Yisrael so that G-d is called Kel El-kei Yisrael
Netziv 33:20 This is according to Chazal who say that gid hanashe was given at Sinai.
There are two ways of learning the Netziv, but this is how Rabbi Triebitz learns it.
The Torah refers here to Yaakov as Yisrael even though his name was not changed until later.
Chullin 101b (and see also 101a). They said to Rabbi Yehuda, It refers to Bnei Yisrael, but they were not called Bnei Yisrael until Sinai. So this verse was stated at Sinai.
The Netziv says that according to Rabbi Yehuda, Yaakov was already called Yisrael even before the angel changed his name. See Harchek Davar ad loc. So Yaakovs sin which caused the rape of Dina cannot have been that he called himself Yisrael.
There was a pre-existing Torah of Bereishit, and later the mitzva of gid hanashe was added into that Torah of Bereishit.
Bereishit 34:5. Dinas brothers come to Yaakov. For they have done a terrible thing in Yisrael
Netziv Harchev Davar (33:20:1). We see here that the Chumash refers to Yaakov as Yisrael, even before Sinai. However he answers that the nation (tribes) were referred to as Yisrael.
The Torah uses the word yeaseh which is pluperfect future. Netziv is sensitive to this, and therefore explains that the verse was inserted later into the narrative.
Similarly, in Akeida it uses the term behar hazeh yiraeh. There too Netziv explains that this verse was inserted after Sinai.
This raises an interesting question. Rabbi Triebitz asks, why can I not say in verse 34:5 And so shall not be done that this also refers to after Sinai?
This verb form has a long history amongst the Rishonim, and will be discussed in the next shiur. But to answer for the Netziv here: He is learning according to Chazal. Since Chazal do not say here that this verse was inserted later, the Netziv is also unable to give this explanation.
Other Rishonim learn that the prohibition here is based on the Noachide laws.
Bava Kama 38b discussing the seven Noachide laws, and the Netziv there also speaks about it.
Netziv writes that while he was writing his commentary, the Ibn Ezra was on his table the entire time.
On the verse here Ibn Ezra refers the reader to Devarim 1:2. There Ibn Ezra speaks of the secret of the twelve verses