Spread the Wealth

Israel is prohibited from uncovering nakedness of anyone who is “flesh of your flesh” (Leviticus 18:6). 

A man and a woman who already have a “flesh” relationship – whether biological or “covenantal” kinship – cannot add another one-flesh sexual relationship. An Israelite can rightly be joined in one flesh with a spouse only by first cutting off flesh. Israelite marriage mimics circumcision. Like sacrifice, marriage requires a division of flesh from flesh before a new union. 

Whatever the logic, the practical effect of this exogamous pressure is clear. If one cannot marry his sister or sister-in-law or daughter or mother, he has to find someone from outside his circle of “flesh” to cleave to as one-flesh in marriage. You can’t keep the wealth (genetic, real property, whatever) in your little flesh-group. It’s got to spread.

Since Leviticus 18 considers fictive, “covenantal” kin relations as “flesh” relations, every wedding makes the flesh group a little bigger and thus pushes the boundaries. Everyone in the flesh-group has to go a little further out to find a spouse.

Excluding flesh-of-flesh marriage pushes Israel away from relations of flesh. It pushes Israel to welcome the stranger into the flesh-group.