John Calvin Commentary Leviticus 20:11

"And the man that lieth with his father`s wife hath uncovered his father`s nakedness: both of them shall surely be put to death; their blood shall be upon them." — Leviticus 20:11 (ASV)

Nothing new occurs here, for Moses's objective was, by enacting penalties, to reinforce the instruction recently given. By previously condemning incestuous marriages, he aimed to summon the Israelites before God, so that their consciences would abhor the crime, even though he gave them no reason to fear earthly judges. Now, however, he alarms them with the threat of punishment, should any indulge themselves with excessive security.

He does not punish the incestuous with rods, as if they were guilty of only a minor offense; instead, he declares it a capital crime if anyone had sinned against the law of nature. First, he condemns the stepmother and stepson to death if they had sexual relations with each other. He then makes the same decree regarding the father-in-law and daughter-in-law, and thirdly, the stepfather and stepdaughter.

However, when a man cohabits simultaneously with a mother and her daughter, he extends the punishment to the mother as well—it must be understood—provided she also consents to the abominable affair. For if a man seduces her daughter against the mother’s will, and the mother is unable to resist it even if she wished to, she is free from guilt.

The same punishment is decreed for a brother and sister, and for a nephew and aunt. It is also extended to relations by marriage (affinity); if anyone should cohabit with his uncle’s wife or his brother’s wife.

We have elsewhere explained the meaning of the expression their blood shall be upon them; that is, that the cause of their death is to be attributed to no one but the flagrant criminals themselves. This is so that their judges, under the guise of humanity, will not shrink from being severe, since it often happens that those who do not fully consider the atrocity of the evil are misled by an empty display of clemency.⁹⁵

Moreover, Moses indirectly suggests that if the guilty are pardoned, vengeance will thus be provoked against the whole people, since iniquity is nurtured by impunity until it bursts forth like a flood.

The penalty of childlessness corresponds to the crime, for it is just that those who have endeavored to corrupt the holy race of Abraham with their adulterous offspring should be exterminated from the world in barrenness.

⁹⁵ “Sont ployables, et faciles a pardoner;” are pliable and easily disposed to pardon. — Fr..