Midrash su Levitico 20:5

The master said above: "Further: For all transgressions, etc., while here (in the case of oath) the punishment extends also to his family." And for all transgressions, you say, punishment is not extended to the family? Behold it is written (Lev. 20, 5) Then I will set My face against this man and against his family. And there is a Baraitha: R. Simon says: "If he has sinned, what has his family done"; to teach thee that in a family, where there is a robber, the entire family is considered robbers, because it conceals him? There he is punished with the punishment attached to his transgression, but the family with a lenient one; while here the family suffers the same punishment as the perjuror himself. As we have learned in the following Baraitha: Rabbi said: "To what purpose is it written in the above-cited verse, I will cut him off, after it reads I will set my face, etc.?" To teach that only him I will cut off but not the whole family. Concerning the punishment of the whole world, etc. Does it not read (Ib. 26, 37) And they shall stumble one over the other, from which it may be intimated that all Israelites are responsible for one another? (Ib. b) The reason there is because they could have prevented the sin by protesting, which they did not do [hence the responsibility]. But is not one's family included in the whole world? There is a difference in the nature of the punishment — viz., his family is punished more rigorously than the rest of the world. The master said above: "If he says, I will swear, the people say: Depart," etc. Why are both the parties called wicked? Let only him who swears have his name. It is in accordance with the opinion of R. Simon b. Tarfon, who says in the following Baraitha (Ex. 22, 10) Then shall an oath of the Lord be between them both. Infer from this that the oath rests upon them both.

14) (Vayikra 20:5) "And I shall cut off him": What is the intent of this (emphasis upon "him")? "He is to be cut off (kareth), and not his family, but they are to suffer afflictions.

15) "And I shall cut off him and all who stray after him to stray after the Molech": to include (as subject to kareth their serving) other idolatries (in one manner of the Molech service). "from the midst of their people": but their people remain at peace.