What would you think about a nephew marrying his aunt—his mother or father’s sister—and starting a family together? It feels creepy, gross, incestuous. In fact, the Torah not once but twice bans nephew-aunt unions.

Do not uncover the nakedness of your father’s sister; she is your father’s flesh. Leviticus 18:12

You shall not uncover the nakedness of your mother’s sister or of your father’s sister, for that is laying bare one’s own flesh; they shall bear their guilt. Leviticus 20:19

Why am I telling you this? What am I leading with this unsavory subject? Because in this week’s portion, the Torah abruptly slams the breaks on the telling of the Exodus story—Moses’s initial demand to Pharaoh to let my people go, Pharaoh’s rejection and demand that the Israelites make the same tally of bricks but gather their own straw, God’s reaffirmation that God has heard their cry and will redeem them, and then the first seven of the ten plagues—the Torah slams the breaks on all this suspense before the plagues begin, to offer a genealogy. Genealogies are eye-glazing. One tends to pass over it to get back to the drama. That would be a mistake.

This genealogy contains a bombshell:

Amram took to wife his father’s sister Jochebed, and she bore him Aaron and Moses…It is the same Aaron and Moses to whom the Lord said, “Bring forth the Israelites from the land of Egypt, troop by troop.” It was they who spoke to Pharaoh king of Egypt to free the Israelites from the Egyptians; these are the same Moses and Aaron. Exodus 6:20 and 26-27.

Turns out, the dry genealogy is not so dry. It makes two points. One, Aaron and Moses are the fruit of a nephew-aunt union that we know to be creepy and incestuous, and that the Torah itself twice prohibits. Two, it is precisely and defiantly this Aaron and Moses that lead the Israelites out of Egypt.

What is Exodus 6 trying to teach us?