Explain the reality about the sources of verbal abuse.

The recommendation of explaining that it isn't the child's fault, or telling the child that it is the parent who has the problem is very unsound advice. You are right in saying, "Wow" in response to the excellent comment, but "wow" in this forum is rather adolescent, as is "reach out." The thing is, as the wise person wrote, "to do." "To show." This isn't a hallmark card situation. The most important thing to do here, is to get the children away from the abusive parent.