Augustine of Hippo
Catena Aurea · Matthäusevangelium 5
For I say unto you, That except your righteousness shall exceed the righteousness of the Scribes and Pharisees, ye shall in no case enter into the kingdom of heaven. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.
(ubi sup.) In the third case are three things; anger, the voice expressive of anger, and a word of reproach, Thou fool. Thus here are three different degrees of sin; in the first when one is angry, but keeps the passion in his heart without giving any sign of it. If again he suffers any sound expressive of the passion to escape him, it is more than had he silently suppressed the rising anger; and if he speaks a word which conveys a direct reproach, it is a yet greater sin.