Heidelberg Catechism · 1563

Q113. What does the tenth commandment require of us?

That not even the slightest thought or desire contrary to any of God's commandments should ever arise in our heart. Rather, we should always hate all sin with all our heart, and delight in all righteousness.
Answer · Heidelberg Catechism

Scripture proofs

  1. [1]
    Psalms 19:7-14

    The law of the Lord is perfect, converting the soul: the testimony of the Lord is sure, making wise the simple. The statutes of the Lord are right, rejoicing the heart: the commandment of the Lord is pure, enlightening the eyes. The fear of the Lord is clean, enduring for ever: the judgments of the Lord are true and righteous altogether. …

    Psalms 139:23-24

    Search me, O God, and know my heart: try me, and know my thoughts: And see if there be any wicked way in me, and lead me in the way everlasting.

    Romans 7:7-8

    What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet. But sin, taking occasion by the commandment, wrought in me all manner of concupiscence. For without the law sin was dead.

Proof texts as given in the original; verse text from the King James Version.