Adultery in the heart
Our Lord has given us a remarkable instance of this in the following words. You have heard that it was said by those of old, You shall not commit adultery (Matthew 5:27). And in explaining this, those blind leaders of the blind (Matthew 15:14) only insist on people abstaining from the outward act. But I say to you that whoever looks at a woman to lust after her has committed adultery with her already in his heart (Matthew 5:28). For God requires truth in the inward parts (Psalm 51:6). He searches the heart and tests the mind (Jeremiah 17:10). And if you incline to iniquity with your heart, the Lord will not hear you (Psalm 66:18).
1771 text
A remarkable instance of this, our Lord has given us, in the following words: Ye have heard, that it was said by them of old time, Thou shalt not commit adultery. And in explaining this, those blind leaders of the blind, only insist on men’s abstaining from the outward act. But I say unto you, whosoever looketh on a woman to lust after her, hath committed adultery with her already in his heart, for God requireth truth in the inward parts. He searcheth the heart and trieth the reins. And if thou incline unto iniquity with thy heart, the Lord will not hear thee.