Then I will set my face. — In that case God himself will show His anger. (See Leviticus 20:3, and Leviticus 17:10.) He will interpose to execute just judgment.
And against his family. — Because they would naturally be privy to it, and aid and abet the father in this crime, they, as well as all those who joined in this idolatrous worship, will be cut off by God himself.