Jesus agrees with God and his word, but he does not agree with the way the religious leaders have applied God's word. The "I" is emphatic. This indicates that what Jesus says is just as important as the original commands. Try to translate this phrase in a way that shows that emphasis. See how you translated this in [Matthew 5:22](../05/22.md).
This metaphor indicates that a man who lusts after a woman is as guilty of adultery as a man who actually commits the act of adultery. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here "heart" is a metonym for a person's thoughts. Alternate translation: "in his mind" or "in his thoughts" (See: [[rc://en/ta/man/jit/figs-metonymy]])