The laws given in this chapter of the book are united by one common feature: they all call attention to crime as a source of impurity, as something that defiles a person. The Torah in general looks at sin as impurity, considering precisely this quality of it the most dangerous and destructive. From the point of view of a believing Yahwist, especially in the pre-exilic era, sin was connected not only and not so much with the violation of a moral norm as with the wall it placed between the sinner and God. Impurity is what keeps a person from being made holy. It is what hinders God's action on a person, the action of God's love and God's breath, which otherwise could change the person and make him part of God's great world. Sin, meanwhile, generates impurity, and impurity separates a person from God so that instead of God's great world, the person finds himself in a little world separated from God, among others separated just as he is.

In pre-Christian times even things not directly connected with sin sometimes defiled a person. For example, the unburied body of someone killed, even if the killer could not be found. It had to be given burial; all the purification rites connected with burial had to be performed, simply because here there was an encounter with death, which never passes without a trace for a person. And with the living, too, not everything is simple.

One may not abandon the woman whom, in Scripture's very precise wording, he "humbled," because, as a modern author very rightly observed, we are responsible for those we tame. One may not step over the natural and lawful interest of one of one's children simply because one likes the mother of another more. One may not trample one's own parents into the mud, whatever they may be like. All this primarily lowers the measure of the fullness of life of the one who acts this way, and therefore of the whole community, which responds accordingly.