Leviticus 18:9-11, or What Constitutes Incest?

This post is pursuant to an issue that a former student raised. I thought somebody might profit from it.

Leviticus 18:9-11

Literal Translation

9. The nakedness of your sister, the daughter of your father or the daughter of your mother, born in the house or born outside, you shall not uncover their nakedness.

10. The nakedness of the daughter of your son or the daughter of your daughter, you shall not uncover their nakedness; for they are your nakedness.

11. The nakedness of the daughter of the wife of your father, born of your father, your sister she is. You shall not uncover her nakedness.

 Comments

The key term here is moledet, which I have translated as “born.” In the twenty or so occurrences of this word in the Old Testament, it appears to have two distinct senses. The first is roughly equivalent to the English “kin,” as for example in Gen 12:1, “Go from your land, and from your kin (moledet), and from the house of your father.” Thus moledet is something between immediate family and  the larger group land or people (see also Esther 2:10, 20). The other sense of moledet is as the feminine participle “born.” That is clearly the meaning in Lev 18:9 and probably the meaning in vs 11. Even if it means “kin” in vs 11 (which I think is unlikely), it still seems to imply a blood relationship.

 The key verses here are 9 and 11. Verse 10 was perhaps included at this point due to the mention of “daughter.” The essential concern is to prohibit the marriage of brother and sister. However, recognizing the complexity of family relations in ancient Israel, the prohibition is given greater specificity. (The statement that “The Scripture does not present a class of people known as step-anything” is erroneous. It does, in fact, recognize such relationships, even though it may not give those relationships a technical name.)

 This greater specificity is as follows: Verse 9 prohibits a man’s marriage to his sister. Obviously the initial reference is to a sibling that shares the same two biological parents. It also prohibits marriage to a step-sister that is the daughter of the man’s father, but not the man’s mother. This was the case of Amnon and Tamar (2 Sam 13). They had the same father (David), but different mothers. The third prohibition is marriage to a daughter of the man’s mother, even though she is not the biological daughter of the man’s father. The verse also rules as irrelevant any consideration of where the “sister” was born. If she is the daughter of the man’s father, or the daughter of the man’s mother, he may not marry her.

 Verse 11 does not appear to add anything to verse 9. It seems to be equivalent to the second prohibition of verse 9. This accounts for the lack of clarity and consistency among the commentators.

 Summary

The text does not seem to include a situation where man A, who has son a, marries woman B who has daughter b, with b being utterly unrelated to A. However, if the ESV rendering is correct, then the passage does address this situation. The problem is that the ESV rendering implies that what makes a and b effectively brother and sister is the fact that they were reared together. That is not true with the case under consideration. In the case under consideration, the children were raised apart, and did not enter into the same family until they were both of marriageable age.

 The WCF says only the following: “Marriage ought not to be within the degrees of consanguinity or affinity forbidden by the Word.” 

 Conclusion

My conclusion is that on the basis of a strict exegesis, the text at most can be read to imply that the marriage of a and b is prohibited. But it does not clearly so state. There may be other considerations that would oppose the marriage of the two, but I don’t see how it can be done on the basis of this text. There may be family considerations and dynamics involved in this particular case that would make the marriage of the two unwise, but on reconsideration, I don’t think Morecraft has an airtight case.