Leviticus 18 the eighteenth chapter of a Book of Leviticus deals with a number of sexual activities considered abominable, including incest, bestiality, and homosexuality or sodomy. The chapter also condemns Moloch worship. It is component of the Holiness Code , and its sexual prohibitions are largely paralleled by , except that chapter 20 has more emphasis on punishment.
The Bible lists several kind of relationship which it regards as incestuous unions; one list appears in the Deuteronomic Code, and two lists arise in the Holiness Code of Leviticus. These lists only mention relationships with female relatives; excluding lesbianism, which implies that the list is addressed to men. These lists then compare as follows:
One feature of all the lists is that sexual activity between a man and his daughter is non explicitly forbidden. The Talmud argues that this is because the prohibition was obvious, especially condition the proscription against a relationship with a granddaughter. The shortness of the list in Leviticus 20, and especially of that in Deuteronomy, is explained by classical Jewish scholarship as being due to the obviousness of the missing prohibitions. The explicit prohibition against engaging in sexual activity with "both a woman and her daughter", implicitly forbids sexual activity between a man and his daughter. Some biblical scholars have instead reported that it was originally in the list but was then accidentally left out from the copy on which innovative versions of the text ultimately depend, due to a mistake by the scribe.
Apart from the questionable issue of a man marrying his daughter, the list in Leviticus 18 roughly produces the same rules as were followed in early pre-Islamic Arabic culture. However, most tribal nations also disliked exogamous marriage—marriage to totally unrelated people. In several prominent cases in the Torah, the incest rules are ignored in favour of marriage to arelative; Jacob is sent as having married his first wife's sister, and Abraham as having a father in common with Sarah rather than a mother, which would hold been permitted by the list. These are non seen as illegal marriages as the incest laws were not precondition until Moses.