Commentators explain that God is not speaking of literal ancestry but of spiritual resemblance. By adopting the idolatry and cruelty of the Canaanites (Hittites and Amorites), Judah had become their spiritual 'daughter.' As John Calvin notes, the proverb 'like mother, like daughter' was used to show that Judah's sins were so notorious they had become a public taunt, demonstrating a complete degeneration from their holy father, Abraham.