Quite an intrusive statement for many external eyes and ears to receive these days. They object saying, "The judgments and thoughts of my heart should belong solely to me." The Word of God differs with that speaker.
Heb. 4:12, "For the word of God is living and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart."
Jesus' Sermon on the Mount in Matthew 5-7 clarifies this requirement in systematic fashion stating, "You have heard that it was said..." (referring to the Word of God), and then He proceeds to explain the internal implications. Do not murder expands from the snuffing of a life to the despising of another. Do not commit adultery expands from an act of infidelity to an unclean thought of another.
No wonder the Pharisees seethed with anger and sinned so. Their hearts previously a private domain were now laid bare for examination by this One? Likewise we cringe to know that every thought and word will have its hearing. And its judgment.
Hope comes only from the psalmist, "I have hidden your word in my heart that I might not sin against you." (Ps. 119:11)