Cain was said to be "of the wicked one". 1 John 3:12
So is most of the world. (Ephesians 2) (Revelation) et al
Likewise, (the other family) (good news)
others are
"Of the Lord your God; whom therefore you must not disparage by unworthy or unbecoming practices, such as here follow, and whom you must not disobey. Ye shall not cut yourselves, nor make any baldness between your eyes, which were the practices of idolaters, both in the worship of their idols, as 1 Kings 18:28; or in their funerals, as here, and Jeremiah 16:6; or upon occasion of public calamities, as Jeremiah 41:5 47:5. See Poole "Leviticus 19:27", See Poole "Leviticus 19:28". See Poole "Leviticus 21:5". For the dead; through excessive sorrow for your dead friends, as if you had no hope of their happiness after death, 1 Thessalonians 4:13.
"
Deuteronomy 14:1 Commentaries: "You are the sons of the LORD your God; you shall not cut yourselves nor shave your forehead for the sake of the dead.
and
Gill's Exposition of the Entire Bible
"Ye are the children of the Lord your God,.... Some of them were so by the special grace of adoption, and all of them by national adoption; which was the peculiar privilege of the people of Israel, and laid them under great obligation to honour and obey the Lord their God, who stood in the relation of a father to them, and they of children to him, Malachi 1:6. The Targum of Jonathan paraphrases it "beloved children"; so the apostle calls the saints; the "dear children of God", who therefore ought to be followers of him, Ephesians 5:1 and for a like reason this relation is observed here, namely, to quicken a regard to the exhortations of the Lord, his cautions, commands, laws, and ordinances, particularly to what follows:"