Calvin's Commentaries, Vol. 5: Harmony of the Law, Part III, tr. by John King, [1847-50], at sacred-texts.com
THE REPETITION OF THE SAME COMMANDMENT
17. Thou shalt not kill.
17. Non occides.
The sum of this Commandment is, that we should not unjustly do violence to any one. In order, however, that God may the better restrain us from all injury of others, He propounds one particular form of it, from which men’s natural sense is abhorrent; for we all detest murder, so as to recoil from those whose hands are polluted with blood, as if they carried contagion with them. Undoubtedly God would have the remains of His image, which still shine forth in men, to continue in some estimation, so that all might feel that every homicide is an offense against Him, (sacrilegium.) He does not, indeed, here express the reason, whereby He elsewhere deters men from murder, i e., by asserting that thus His image is violated, (Ge 9:6;) yet, however precisely and authoritatively He may speak as a Legislator, He would still have us consider, what might naturally occur to everybody’s mind, such as the statement of Isa 58:7, that man is our “own flesh.” In order, then, that believers may more diligently beware of inflicting injuries, He condemns a crime, which all spontaneously confess to be insufferable. It will, however, more clearly appear hereafter, that under the word kill is included by synecdoche all violence, smiting, and aggression. Besides, another principle is also to be remembered, that in negative precepts, as they are called, the opposite affirmation is also to be understood; else it would not be by any means consistent, that a person would satisfy God’s Law by merely abstaining from doing injury to others. Suppose, for example, that one of a cowardly disposition, and not daring to assail even a child, should not move a finger to injure his neighbors, would he therefore have discharged the duties of humanity as regards the Sixth Commandment? Nay, natural common sense demands more than that we should abstain from wrongdoing. And, not to say more on this point, it will plainly appear from the summary of the Second Table, that God not only forbids us to be murderers, but also prescribes that every one should study faithfully to defend the life of his neighbor, and practically to declare that it is dear to him; for in that summary no mere negative phrase is used, but the words expressly set forth that our neighbors are to be loved. It is unquestionable, then, that of those whom God there commands to be loved, He here commends the lives to our care. There are, consequently, two parts in the Commandment, — first, that we should not vex, or oppress, or be at enmity with any; and, secondly, that we should not only live at peace with men, without exciting quarrels, but also should aid, as far as we can, the miserable who are unjustly oppressed, and should endeavor to resist the wicked, lest they should injure men as they list. Christ, therefore, in expounding the genuine sense of the Law, not only pronounces those transgressors who have committed murder, but also that
“he shall be in danger of the judgment who is angry with his brother without a cause; 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.” (Mt 5:22.)
For He does not there, as some have ignorantly supposed, frame t~ new law, as if to east blame upon His Father; but shows the folly and perversity of those interpreters of the Law who only insist on the external appearance, and husk of things, as is vulgarly said; since the doctrine of God must rather be estimated from a due consideration of. His nature. Before earthly judges, if a man have carried a weapon for the purpose of killing a man, he is found guilty of violence; and God, who is a spiritual Lawgiver, goes even further. With Him, therefore, anger is accounted murder; yea, inasmuch as He pierces even to the most secret feelings, He holds even concealed hatred to be murder; for so we must understand John’s words, “Whosoever hateth his brother is a murderer,” (1Jo 3:15;) i.e., hatred conceived in the heart is sufficient for his condemnation, although it may not openly appear.