9 But these things we have said, as one might say them incidentally, concerning all the commandments. Now we must go on to that which is before us, and keep to the thread of what had been affirmed. “He that is angry with his brother without a cause shall be in danger of the judgment:” so He speaks. Thus He has not altogether taken the thing away: first, because it is not possible, being a man, to be freed from passions: we may indeed get the dominion over them, but to be altogether without them is out of the question.
Next, because this passion is even useful, if we know how to use it at the suitable time. See, for instance, what great good was wrought by that anger of Paul, which he felt against the Corinthians, on that well-known occasion; and how, as it delivered them from a grievous pest, so by the same means again he recovered the people of the Galatians likewise, which had fallen aside; and others too beside these. What then is the proper time for anger? When we are not avenging ourselves, but checking others in their lawless freaks, or forcing them to attend in their negligence.
And what is the unsuitable time? When we do so as avenging ourselves: which Paul also forbidding, said “Avenge not yourselves, dearly beloved, but rather give place unto wrath.” When we are contending for riches: yea, for this has he also taken away, where he says, “Why do ye not rather take wrong? Why do ye not rather suffer yourselves to be defrauded?” For as this last sort is superfluous, so is the first necessary and profitable. But most men do the contrary; becoming like wild beasts when they are injured themselves, but remiss and cowardly when they see despite done to another: both which are just opposite to the laws of the Gospel.
Being angry then is not a transgression, but being so unseasonably. For this cause the prophet also said, “Be angry, and sin not.”
10. “And whosoever shall say to his brother, Raca, shall be in danger of the council.”
By the council in this place He means the tribunal of the Hebrews: and He has mentioned this now, on purpose that He might not seem everywhere to play the stranger and innovator.
But this word, “Raca,” is not an expression of a great insolence, but rather of some contempt and slight on the part of the speaker. For as we, giving orders either to our servants, or to any very inferior person, say, “Away with you; you here, tell such an one:” so they who make use of the Syrians' language say, “Raca,” putting that word instead of “you.” But God, the lover of man, roots up even the least faults, commanding us to behave to one another in seemly manner, and with due respect; and this with a view of destroying hereby also the greater.
“But whosoever shall say, You fool, shall be in danger of hell fire.”
To many this commandment has appeared grievous and galling, if for a mere word we are really to pay so great a penalty. And some even say that it was spoken rather hyperbolically. But I fear lest, when we have deceived ourselves with words here, we may in deeds there suffer that extreme punishment.
For wherefore, tell me, does the commandment seem overburdensome? Do you not know that most punishments and most sins have their beginning from words? Yea, for by words are blasphemies, and denials are by words, and revilings, and reproaches, and perjuries, and bearing false witness. Regard not then its being a mere word, but whether it have not much danger, this do thou inquire. Are you ignorant that in the season of enmity, when wrath is inflamed, and the soul kindled, even the least thing appears great, and what is not very reproachful is counted intolerable? And often these little things have given birth even to murder, and overthrown whole cities. For just as where friendship is, even grievous things are light, so where enmity lies beneath, very trifles appear intolerable. And however simply a word be spoken, it is surmised to have been spoken with an evil meaning. And as in fire: if there be but a small spark, though thousands of planks lie by, it does not easily lay hold of them; but if the flame have waxed strong and high, it readily seizes not planks only, but stones, and all materials that fall in its way; and by what things it is usually quenched, by the same it is kindled the more (for some say that at such a time not only wood and tow, and the other combustibles, but even water darted forth upon it does but fan its power the more); so is it also with anger; whatever any one may say, becomes food in a moment for this evil conflagration. All which kind of evils Christ checking beforehand, had condemned first him that is angry without a cause to the judgment, (this being the very reason why He said, “He that is angry shall be in danger of the judgment”); then him that says “Raca,” to the council. But as yet these are no great things; for the punishments are here. Therefore for him who calls “fool” He has added the fire of hell, now for the first time mentioning the name of hell. For having before discoursed much of the kingdom, not until then did He mention this; implying, that the former comes of His own love and indulgence towards man, this latter of our negligence.
Source: Homilies on the Gospel of St. Matthew (New Advent)