The Law kept by Love.
I. In dealing with this principle our Lord adduces certain examples by way of illustration, and asserts for Himself a high right and authority to declare to the people the very will of God in this matter. He reminds them of certain things which had been said by "them of old time." Of these sayings some are selected from the Ten Commandments, some from other parts of the Mosaic law, and some apparently from the glosses of the scribes and Pharisees. But no matter with what authority they had been spoken, Jesus claims it as His prerogative to enlarge, or to alter, them by His own authority.
II. The first of the Divine commandments which He handles here, with the view of showing its real spiritual character, is that which concerns the preservation of human life. It had been said by them of old time, and, in fact, by God, "Thou shalt not kill." Christ taught that, in the sight of God, the causeless anger, the cruel scorn, the malignant speech were all infractions of this law, and would all receive one day their merited and fitting punishment. There might be gradations in the amount of guilt, and all these would doubtless be taken into account, and the penalty rightly adjusted to the crime. But this, at any rate, is certain, the law "Thou shalt not kill" might be broken not merely by the violent invasion of life, but also by the wicked tongue and the cruel thought; and for all these alike God will bring us into judgment.
III. In its true spirit this law can be kept only when we love each other as Christ hath loved us. And if we yield ourselves either to wrathful and bitter thoughts, or to contemptuous and malicious words, our offerings, and prayers, and devotions, and all other our most pious services, in which we seem to delight, shall not be accepted at the throne of grace, shall not obtain the blessing from the God of our salvation, and shall not bring to us the joy which they are meant to bring.
W. C. Smith, The Sermon on the Mount,p. 82.
References: Matthew 5:21. H. D. Rawnsley, Christian World Pulpit,vol. xxxii., p. 154.Matthew 5:21; Matthew 5:22. Parker, Hidden Springs,p. 301.Matthew 5:21-26. J. Oswald Dykes, The Laws of the Kingdom,p. 23; Ibid., The Manifesto of the King,p. 223.Matthew 5:21-32. Parker, Inner Life of Christ,vol. i., p. 183.Matthew 5:23. J. M. Neale, Sermons in Sackville College,vol. ii., p. 70. Matthew 5:23; Matthew 5:24. Clergyman's Magazine,vol. iii., p. 89.