Following her rape, at the hands of Shechem, Dina disapears from the narrative. Her fate is the subject of some rabbinical speculation, with one interpretive tradition saying she became the wife of her full-brother Shimon, and another saying she married Job. [Another interprtation, provided in the modern midrash The Red Tent by Anita Diamont, has her eventually finding her way to Egypt and reuniting with her family.]
The Shimon midrash appears to be based on a textual anoamly in the story of Dina's rescue. We're told:
אֶת־חֲמֹור֙ וְאֶת־שְׁכֶ֣ם בְּנֹ֔ו הָרְג֖וּ לְפִי־חָ֑רֶב וַיִּקְח֧וּ אֶת־דִּינָ֛ה מִבֵּ֥ית שְׁכֶ֖ם וַיֵּצֵֽאוּ׃
They killed Hamor and his son Shechem with the edge of the sword, and took Dinah from Shechem's house, and went forth.
The verb "and they took" can also mean "they married" (ie took as a wife) and it appears redundant to say they both took her, and left with her. The rescue was carried out by Shimon and Levi together, though I don't know why Shimon, and not Levi is the presumed groom. Perhaps because he was older? Or maybe, this is a way to save Shimon from the perceived error of marrying a Canaanite. Elsewhere (Ex 6:15) we're introduced to Shaul, the son of Shimon and "a Caanantie woman." The midrash says this woman is actually Dina, and Saul is the son she had with Shechem. (Though I hasten to add that R. Nechemia, a Tanna, said all the brothers married Canaanite women, so presumably he did not accept or know of this tradition.)
The Job midrash, the Talmud says, is sourced in word-play. Job tells his wife כדבר אחת הנבלות תדברי you speak as an impious woman and about Shechem's attack, the Torah says כי נבלה עשה בישראל he had done a disgraceful thing in Israel*. The idea seems to be that Shechem turned Dina into נבלה and later Job's wife is identified with the same word.
Though I think the Shimon midrash is based on the text, my hunch is that the prooftext provided in the Talmud for the Job midrash is actually a retro-reason, that is a reason provided after the fact to explain an exisiting tradition.
I say this, both because the connection based on a single word seems fanciful, and also because James Kugel, in The Bible as it Was shows that the Dina-was-Job's wife tradition dates to Testament of Job (a pseudepigraphic work originally composed in Greek perhaps, Kugel speculates, by a Christian in the first century, but more likely by a Greek-speaking Jew a few centuries earlier.
In this book, Job calls himself a "son of Esav" suggesting the original source of the Dina-was-Job's wife tradition is not the appearance of the word נבלה but the belief that Esav's descendant Jobab was actually Job. (a similarity that I suppose is much more pronounced in Greek.)
Additionally, the Talmud does not identify the author of Dina-was-Job's wife tradition, suggesting that it was merely something everyone knew, that the redactor of the Talmud (ie the Sevoraim who didn't speak Greek) were now trying to justify after many centuries had passed. (Counter argument: Berashis Rabbah attributes the Dina-was-Job's wife tradition to Abbah bar Khana. I don't know when Abbah Bar Khana lived, and Berashis Rabba dates to around the time of the Talmud, so this attribution doesn't necessarily defeat my suggestions; moreover Dina is identified as Job's wife in Philo, and in the Job Targum.)
* The claim that כי נבלה עשה בישראל he had done a disgraceful thing in Israel* seems like an anachronism. In Deuteronomy a promiscuous daughter is also said to have committed נְבָלָה...בְיִשְׂרָאֵל a disgraceful thing in Israel. The rape of Dina is described with the same phrase, though "Israel," at that moment, consisted of just Jacob and his 12 sons.
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