Read this: Historical definitions of Jewish identity have traditionally been based on halakhic definitions of matrilineal descent, and halakhic conversions. Historical definitions of who is a Jew date back to the codification of the Oral Torah into the Babylonian Talmud, around 200 CE. Interpretations of sections of the Tanakh, such as Deuteronomy 7:15, by Jewish sages, are used as a warning against intermarriage between Jews and Canaanites because "[the non-Jewish husband] will cause your child to turn away from Me and they will worship the gods (i.e., idols) of others." Leviticus 24:10 says that the son in a marriage between a Hebrew woman and an Egyptian man is "of the community of Israel." This is complemented by Ezra 10:23, where Israelites returning from Babylon vow to put aside their gentile wives and their children. Since the anti-religious Haskalah movement of the late 18th and 19th centuries, halakhic interpretations of Jewish identity have been challenged.

What interpretations of Jewish identity have never been challenged?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable