Incest in The Bible - Definition

Definition

In ancient times, tribal nations preferred endogamous marriage - marriage to one's relatives; the ideal marriage was usually that to a cousin, and it was often forbidden for an eldest daughter to even marry outside the family. Marriage to a half-sister, for example, is considered incest by most nations today, but was common behaviour for Egyptian pharaohs; similarly, the Book of Genesis portrays Sarah as marrying Abraham, her half-brother, without criticising the close genetic relationship between them, and the Book of Samuel treats the marriage of a royal prince to his sister as unusual, rather than wicked. The issue of consanguinity is thus a complicated one, and the exact definition of incest varies throughout the Bible and Rabbinical literature.

The Holiness Code of Leviticus elaborates in detail the relationships it regards as incestuous unions, and two chapters later specifies punishments for specific incestuous unions, but this second list of unions is much shorter than the first; textual scholars regard these two lists as having originally been independent documents, bound together at a later point. The Deuteronomic Code, gives a yet more simple list of forbidden relationships - just parent's daughter (including sister), father's wife (including mother), and mother-in-law. These lists only mention relationships with female relatives; excluding lesbianism, this implies that the list is addressed to men. These lists of forbidden unions compare as follows (the relations highlighted in red are those that are forbidden):

One of the most notable features of all the lists is that sexual activity between a man and his own daughter is not explicitly forbidden, although the first relation mentioned after the Levitical prohibition of sex with "near kin" is that of "thy father." The talmud argues that this absence is because the prohibition was obvious, especially given the proscription against a relationship with a granddaughter, although some biblical scholars have instead proposed that it was originally in the list, but was then accidentally left out from the copy on which modern versions of the text ultimately depend, due to a mistake by the scribe. The second list in the Holiness code noticeably differs from the first by not including the closer relatives, and it might be assumed that obviousness is the explanation here as well.

Apart from the case of the daughter, the first incest list in the Holiness code roughly produces the same rules as were followed in early (pre-Islamic) Arabic culture; in Islam, these pre-existing rules were made statutory. The rules in this list are, however, ignored in several prominent cases in the Torah - Jacob is described as having married his first wife's sister, and Abraham as having a father in common with Sarah (rather than a mother, which would have been permitted by the list).

Ezekiel implies that, in his time, marriage between a man and his stepmother, or his daughter-in-law, or his sister, were frequent. This situation seems to be the target of the Deuteronomic version of the incest prohibition, which only addresses roughly the same three issues (though prohibiting the mother-in-law in place of the daughter-in-law). Early rabbinic commentators instead argue that the Deuteronomic list is so short because the other possible liaisons were obviously prohibited, and these three were the only liaisons difficult to detect, on account of the fact that, in their day, a man's stepmother, half-sister, and mother-in-law usually lived in the same house as the man (prior to any liaison).