The Book of Genesis tells stories that concern a time before the existential events that make up the Book of Exodus where, among other things, the idea of law as providing guidance for how people are to conduct themselves makes its entrance. The Book of the Covenant had indeed provided a kind of international compact whereby families that resembled those of the patriarchs were supposed to regulate their relations with one another through establishing rules of compensation for damages, but the editors of the Five Books of Moses chose to include this passage in Exodus, as if to indicate that the Book of Genesis was to be truly prior to the concept of law. But if that were the case, how were the people of the Book of Genesis “supposed” to behave, that term itself rushing us to impose the imperative of law--”should”-- on the pre-legal condition. Was it supposed to be that mere custom and godly edict would be enough to explain how people behaved and behaved themselves? Not so, because the pre-legal people of Genesis used their minds to consider their interests, however difficult it may be not to assume that they were making legal type judgments. When Jacob learns that his sons had killed the people who had offered to circumcise themselves as well as intermarry with Jacob’s tribe because one of them had taken one of their sisters for a wife, Jacob does not excoriate his sons for having been vengeful or otherwise done evil, but simply concludes that the tribe will have to move on now rather than settle there. That can be taken as an ironic understatement, meant to foretell that those descended from the Old Testament  families would always, sooner or later, have to move on, or that Jacob was making a silent judgment about their actions-- though I have done so myself in an earlier reading of this story of the rape of Dinah-- but, rather, that Jacob was simply not given to the moral reasoning that would come with the arrival of law.