Against his family, i.e. either,
1. His posterity, whom God threatened to punish for their father's idolatry, Exo 20. Or,
2. His people, as that word is used, Jeremiah 8:3 Micah 2:3, to wit, the people of that land, who by their connivance make themselves guilty of his sin, Leviticus 20:4. Or,
3. His disciples and followers, who are oft called the sons or children of their masters. And so it may seem to be explained in the following words, all that go a whoring after him, as the first clause, which concerns the head or chief person himself, I will set my face against that man, is explained by these words, I will cut him off.