Was Jewishness Always Matrilineal?

Question:

Moses married the daughter of a non-Jewish priest. Though she apparently converted later on, she was not Jewish when Moses married her, although she may have followed his faith and convictions. But Moses' children were clearly Jewish.

Although it may not be palatable, I would suggest that the guidelines were different in biblical times. Men were able to continue the Jewish line without a Jewish wife.

Answer:

Moses was not the only one to marry out of the tribe. Joseph married an Egyptian woman and, according to some opinions, his brothers married Canaanites. For that matter, what made Rachel, Leah or Rebecca more Jewish than anyone else?

The answer is, nothing at all. Because there was no Jewish People at the time.

The Jewish Nation was formed at the event of Mount Sinai. Before that, they were descendants of a common father, Jacob, along with many who had come to join or married into their families. Standing at Mount Sinai, they were chosen and appointed a "kingdom of priests and a holy nation." They became a people.

In other words, at that point everyone standing there—including Zipporah, Moses' wife, including even Moses himself—all became Jewish.

Since then, if a person wants to join the Jewish People, s/he must undergo that same experience of Mount Sinai—without the fireworks. Meaning, accept the Torah and all its mitzvahs, as is required from a holy people that is meant to be a light to the nations.

Since the people there had also immersed in water (that's the traditional understanding of the instructions at Exodus 19:10), the prospective convert must also immerse in a mikvah. Since the men were circumcised beforehand, a male who wishes to convert must be circumcised. The other requirement is to bring an animal sacrifice as they did there, but without a Temple standing in Jerusalem, this will have to wait.

There are stories later in the times of the Judges and the Kings, where Jewish men took wives from other peoples. In most cases, there is nothing mentioned about their acceptance of the mitzvahs or dipping in a mikvah.

This, however, is quite understandable. The reader takes it as obvious. Something like if I would write, "And then Vicki York went to Harvard and received her doctorate in sociology." I don't need to write that Vicki wrote a thesis and defended it—the contemporary reader understands that as obvious. Similarly, it would be superfluous for the Bible to account all the details of how this woman became part of our people.

This entire confusion of maternal vs. paternal line arises out of a general misconception of Jewish identity. As I have written many times, being Jewish is not a matter of belief but of belonging. A Jew is one who belongs to a people who have a covenant with G‑d. In that sense, we are far better understood as a tribe rather than as a religion. And in tribal terms, when a man marries a woman from outside the tribe, all understand that he is bringing her in to join the tribe and so she must go through whatever rites are required to make that entry.

Hope this explains things a little further.

Rabbi Tzvi Freeman for Chabad.org