But I say to you that everyone who continues to be angry with his brother or harbors malice against him shall be guilty before the court; and whoever speaks [contemptuously and insultingly] to his brother, ‘Raca (You empty-headed idiot)!’ shall be guilty before the supreme court (Sanhedrin); and whoever says, ‘You fool!’ shall be in danger of the fiery hell.

So if you are presenting your offering at the altar, and while there you remember that your brother has something [such as a grievance or legitimate complaint] against you,

“Brother will betray brother to death, and the father his child; and children will rise up and rebel against their parents and cause them to be put death.

Forgiveness

Then Peter came to Him and asked, “Lord, how many times will my brother sin against me and I forgive him and let it go? Up to seven times?”