Matthew 5:21-22 (NIV)
“You have heard that it was said to the people long ago,
You shall not murder, and anyone who murders will be subject to judgment.’
BUT I tell you that anyone who is angry with a brother or sister will be subject to judgment.
Again, anyone who says to a brother or sister, ‘Raca,’ is answerable to the court. And anyone who says, ‘You fool!’ will be in danger of the fire of hell.