Taboos against incest exist in all cultures; what varies is which relationships are considered incestuous. This week’s double Torah portion, Acharey Mot and Kedoshim, includes two overlapping lists of family members who are forbidden as sexual partners. Yet father-daughter sex is not mentioned.
Any man may not approach any flesh of his flesh to uncover nakedness. (Leviticus/Vayikra 18:6)
Both lists are about incest between men and females; homosexual incest is not considered, perhaps because both Torah portions also forbids lying down with a man “like lying down with a woman”.1
Together the two lists forbid “any man” from “lying down with” his mother, another of his father’s wives, his mother-in-law, his sister or half-sister, his granddaughter, his aunt (by blood or marriage), his brother’s wife, or his daughter-in-law.2 A man is also forbidden to marry a woman and her mother.3
Abraham says his wife, Sarah, is his half-sister when he is explaining himself to King Avimelekh.4 But since he previously deceived Avimelekh by pretending Sarah was unmarried, the reader cannot be sure he is telling the truth.
Neither list mentions sex between a man and his niece. Was it acceptable? In the book of Genesis, Nachor marries his niece Milcah.5 In Joshua and Judges, Caleb’s daughter Achsah marries Otniel, but it is ambiguous whether Otniel is Caleb’s younger brother or younger kinsman.6 Midrash from the first millennium C.E. turns some other marriages in the Torah into uncle-niece unions without real support from the biblical text. The Talmud, however, approves of a man marrying his niece on the ground that he is already fond of her:
One who loves his neighbors … and who marries the daughter of his sister, a woman he knows and is fond of as a family relative and not only as a wife … about him the verse states: “Then shall you call, and the Lord will answer; you shall cry, and He will say: Here I am” (Isaiah 58:9). (Yevamot 62b-63a)7
The most egregious omission in the incest lists in Acharey Mot and Kedoshim is sex between a father and his daughter. Yet we know, from a story in the book of Genesis, that calling someone a child of such a union is an insult.
When God is about to destroy Sodom and Gomorrah, two angels pull Lot, his wife, and his two unmarried daughters out of their house in Sodom and urge them to flee. Lot’s wife looks back and becomes a pillar of salt, but the other three travel on and move into a cave in the hills above the fire-blasted plain.
And the older one said to the younger one: “Our father is old, and there is no man on the earth to come into us in the way of all the earth. Go, let us make our father drink wine, and let us lie down with him, and we will stay alive through our father’s seed.” (Genesis 19:31-32)
They take turns, the older daughter lying with him on the first night, the younger on the second night.
And the two daughters of Lot became pregnant by their father. And the child of the older one was a son, and she called his name Moav; he is the father of [the people of] Moav to this day. And the younger one, she also became pregnant with a son, and she called his name Ben-Ammi; he is the father of the children of Ammon to this day. (Genesis 19:36-38)
The political point of this tale is to denigrate the neighboring kingdoms of Moav and Ammon by claiming that their founding fathers are the children of incest.8 It was probably all too common for men to molest their underage daughters then, as it is today. But a story about adult women molesting their father might seem both humorous and sordid to the ancient Israelites—and therefore an effective way to bias the listeners toward supporting the Kingdom of Israel’s occasional wars with Moav and/or Ammon over territory on the east side of the Jordan River.9
Within the storyline of Genesis, Lot’s daughters are not disobeying God. There are no divine laws against incest until this week’s double portion in Leviticus, and the only statement in those lists that could apply to a father-daughter liaison is the introductory “Any man may not approach any flesh of his flesh to uncover nakedness”. The book of Genesis does not use this general divine rule retroactively; Nachor’s marriage to his niece and Abraham’s claim that he married his half-sister pass without censure.
If the decision of Lot’s daughters to use their father in order to have children does not count as disobeying God, does it count as an immoral act?
I examine this question in the book I am writing about moral psychology in Genesis, and conclude that even if there really were no other men in left alive on earth, it would be wrong to produce children who would have no opportunity for satisfying lives in an empty world. Lot’s two daughters are understandably traumatized (and not thinking clearly, or they would realize the earth is not entirely depopulated). But they would be more righteous if they denied themselves the comfort children could bring them.
Ethical reasons for avoiding incest include drawbacks for the children of the union (although in most cases the drawback is an increased chance of genetic diseases). But there is a compelling ethical reason to avoid incest even when no children result: the combination of incompatible roles. The worst combination is when a parent, who exercises authority over and responsibility for a child, has sex with the child, who tries to please the powerful parent and cannot give free consent. This is child abuse, and plainly unethical, whether God condemns it or not.
When Lot’s daughters render their father helpless through drink and then take advantage of him, are they committing elder abuse?
- Leviticus 18:22 and 20:13.
- Leviticus 18:7-16, 20:11-12, 20:17, 20:19-21. Genesis 38:6-26 makes an exception to the rule about sex with one’s daughter-in-law.
- Leviticus 20:14.
- Genesis 20:12.
- Genesis 11:29. Nachor is Abraham’s brother. Subsequently Abraham’s son Isaac marries their granddaughter Rebecca, Isaac’s first cousin once removed. Then Isaac and Rebecca’s son Jacob marries Leah and Rachel, his uncle Lavan’s daughters and his own first cousins.
- Caleb is listed as “ben Yefuneh” in Numbers 13:6. Judges 1:13 says: And Otniel, ben Kenaz, the younger achi of Caleb, captured it for him, and he gave him Akhsah, his daughter, for a wife. Ben (בֶּן) = son of, male descendant of. Achi (אֲחִי) = brother of, kinsman of.
- William Davidson translation, sefaria.org.
- The names of the two sons are examples of folk etymology. Moab, Moav (מוֹאָב) in Hebrew, is explained as m- (מְ) = from + av (אָב) = father. Ben-Ammi (בֶּן־עַמִּי) means “child of Ammon” or “Ammonite”, but it is also ben (בֶּן) = child of, son of + ammi (עַמִּי) = my paternal relatives.
- See Judges 3:26-30, 11:29-33; 1 Samuel 11:1-13; 2 Samuel 8:2, 12:26-31; 2 Kings 3:4-27.