You have heard that it was said by them of old time, You shall not commit adultery:
All Commentaries on Matthew 5:27 Go To Matthew 5
Cornelius a Lapide
AD 1637
Ye have heard, &c. . . to lust after her—that Isaiah , with the design and object of indulging sinful passion with her—hath already committed adultery with her in his heart. Because by adultery he hath already corrupted her in his mind, and therefore before God, who beholds the heart, he is an adulterer, and as an adulterer he will be punished by Him.
Christ passes from anger to concupiscence, because these two passions have the greatest influence over men. And as He explained the commandment, Thou shall nor kill, to forbid anger, so He here explains Thou shall not commit adultery to forbid concupiscence. For many of the Scribes and Pharisees greatly erred in their exposition of this precept as well as of the former. For although they knew that it was commanded by the tenth precept of the Decalogue, Thou shall not covet thy neighbour"s wife, nevertheless they erred—1. Because they understood it of concupiscence, not altogether internal, but such as is wont to break out in touch, kisses, lascivious words, and such like, according to the maxim, "The law prohibits the hand, not the mind." But this is true of civil and state law, which only punishes external wrongdoing, but not of the law of God, which weighs and chastises the inmost thoughts of the heart. Josephus, the Jewish historian, fell into this very mistake, when, in the twelfth book of his Antiquities, he cites Polybius as saying that Antiochus Epiphanes perished miserably because he had wished to spoil the temple of Diana. Josephus finds fault with Polybius, saying, "To have wished merely, and not to have effected the sacrilege, does not seem a thing worthy of punishment." And R. David Kimchi, cited by Gerebrard (Ps. lxvi.), says, "Even if I should see iniquity in my heart, which I was even prepared to carry out in Acts , that it should be in the presence of God, and if I should utter it with my lips, yet will not God hear it—i.e, it will not be imputed to me for wickedness. For God does not reckon an evil thought as a work, unless it be against the faith of God and religion." Thus, too, there are many in this day who say, "To think evil is not a sin, but to do evil."
But this is a crass error, known and confuted by Aristotle and other heathens. For free will is the proper test and criterion of goodness and wickedness, of virtue and vice. For if free will seeks what is good and honest, it is itself good and laudable; but if evil, it is evil and blameworthy. Wherefore the external Acts , as, for instance, of adultery, is not, speaking precisely, a sin in itself (as in plain from the case of idiots being adulterers), unless it proceeded from free will. For from free will it derives all its formal sinfulness.
2. The Scribes erred in thinking that immodest looks, touch, kisses, &c, were not sins of adultery and fornication, but of concupiscence, and so were done against the Tenth Commandment, Thou shalt not covet thy neighbour"s wife, but not against the Seventh. In opposition to this Christ here teaches the contrary, and so expounds the Seventh Commandment that all impurity is forbidden by it, because all such things are the road to adultery, and so a kind of beginning of adultery.
3. They were in error who thought that by this commandment only concupiscence in respect to another man"s wife, but not of any unmarried woman, was forbidden. This error Christ here corrects, and teaches that all impurity between the sexes is forbidden by this law.
