The Catechism in Questions & Answers

351. What is the significance of the Seventh Commandment in the New Testament?

Jesus described theft as a sin. Theft has its source in the heart of the individual: “For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies. These are the things which defile a man” (Matthew 15: 19, 20).