The Catechism in Questions & Answers

362. What is the significance of the Ninth and Tenth Commandments in the Old Testament?

Since the beginning of time, Satan has sought to tempt human beings to sin by awakening within them the desire and lust for forbidden things.
The Old Testament relates an example of the extreme consequences that resulted from King David’s desire for the wife of his neighbour. This desire eventually led him to deceive, commit adultery, and commit murder (cf. 2 Samuel 11).