This is the answer…
Jesus was not teaching about language in the first passage. The actual words used are not the point. Jesus was using what was common knowledge at the time, how the Jewish court systems worked, to illustrate liability and possible punishment for various types of and severity of sin. Jesus equates anger with killing and says that it is just as bad and goes on from there…
**"You have heard that it was said to the men of old,
You shall not kill; and whoever kills shall be liable to judgment**.' But I say to you that every one who is angry with his brother shall be liable to judgment; whoever insults his brother shall be liable to the court, and whoever says,You fool!’ shall be liable to the council. (Matthew 5:21-22)
*]The first sin, anger in the heart, is internal. No words are spoken to anyone else but you feel anger. This leaves you liable to judgement.
*]The second sin is when you say something to “your brother” with whom you are angry. Your anger becomes external and you hurt the person with whom you are angry with your words. This external sin leaves you liable to “the court” which is a reference to the small claims and civil courts at the gates of the city which could sentence you to prison.
*]The third sin is a public statement - you call someone a fool publicly. You hurth them and you damage their name in a public setting. This leaves you liable to “the council” which is a reference to the Jewish Sanhedrin, the supreme court of Israel, which could sentence you to death.
It is about levels of sin; 1) internal anger - liable to judgement, 2) angry words directed at another person - liable to the court and, 3) publicly smearing someone’s name - liable to death. These have varying levels of liability based on their severity and scope and even anger is as bad as killing.
Jesus is raising the bar on the Jewish view of sin.