"If you are angry, why do you know how to do good to your children, and if you are considered kind and cordial, then why do not you do as good to our children as to your children?"
This quote from Ivan the Fourth means that an evil person harms enemies with anger, the child is only good and the child that the evil person gave birth, that is, to the wife who is either obedient or the same as the husband, but it is logical that this creation created from his living bacteria and organisms, and that it is unlikely that he will desire only evil, namely, he will teach him to do evil, and the good ones are strictly and fairly educated so that the child becomes stronger, understood what is necessary and what is not allowed, the evil ones allow their children do what they want, and if you say that hearty and kind, then it's affairs over prove, not just to say it.
That's what this quote means.