MATTHEW 5: 21-22
The law of Murder

21. You have heard that the ancients were told, "You Shall Not Commit Murder" and "Whoever commits murder shall be liable to the court".
22. But I say to you that everyone who is angry with his brother shall be guilty before the court and whoever shall say to his brother, "Raca", shall be guilty before the supreme court; and whoever shall say, "You fool", shall be guilty enough to go into the fiery hell.

(Raca probably means "empty-head"; fiery hell--the word translated "hell" is Geenna or Gehenna, a place in the valley of Hinnom where human sacrifices had been offered--see Jeremiah 7:31)