Charles Spurgeon Commentary Matthew 5:27-28

"Ye have heard that it was said, Thou shalt not commit adultery: but I say unto you, that every one that looketh on a woman to lust after her hath committed adultery with her already in his heart." — Matthew 5:27-28 (ASV)

Ye have heard that it was said by them of old time, Thou shalt not commit adultery: but I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

So that the unholy desire, the lascivious glance, everything that approaches licentiousness, is here condemned; and Christ is proved to be not the Abrogator of the law, but the Confirmer of it.

See how he shows that the commandment is exceedingly broad, wide as the canopy of heaven, all-embracing. How sternly it condemns us all, and how fitting it is for us to fall down at the feet of the God of infinite mercy, and seek his forgiveness.

"It is mercy – mercy we implore,
We would your pity move;
Your grace is an inexhaustible store,
And you yourself are Love."

In this case, our King again sets aside the interpretations of men concerning the commands of God and reveals the law in its vast spiritual breadth. Whereas tradition had confined the prohibition to an overt act of unchastity, the King shows that it forbade the unclean desires of the heart.

Here the divine law is shown to refer, not only to the act of adultery, but even to the desire, imagination, or passion which would suggest such an infamy. What a King is ours, who stretches His scepter over the realm of our inward lusts! How sovereignly He puts it, But I say unto you! Who but a divine being has authority to speak in this way? His word is law.

So it ought to be, since He touches vice at the fountain-head and forbids uncleanness in the heart. If sin were not allowed in the mind, it would never be made manifest in the body. This, therefore, is a very effective way of dealing with them. But how searching, how condemning! Irregular looks, unchaste desires, and strong passions are of the very essence of adultery, and who can claim a lifelong freedom from them? Yet these are the things which defile a man. Lord, purge them out of my nature and make me pure within.