Commentators explain that this verse directly refutes the popular excuse of the time: "The fathers have eaten a sour grape, and the children's teeth are set on edge." The people were blaming their ancestors for their suffering to avoid repenting for their own sins. God makes it clear that under His just rule, each person is ultimately accountable for their own iniquity. The one who eats the "sour grape" of sin is the one who will experience its bitter consequences.