Matthew 5:22
New International Version (NIV)
22 “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.“
From BibleGateway.com: http://www.biblegateway.com/passage/?search=Matthew 5:22&version=NIV
NIV®