Catechism of the Catholic Church
You shall not covet ... anything that is your neighbor's.... You shall not desire your neighbor's house, his field, or his manservant, or his maidservant,, or his ox, or his ass, or anything that is your neighbor's. 317
For where your treasure is, there will your heart be also. 318
2534 The tenth commandment unfolds and completes the ninth, which is concerned with concupiscence of the flesh. It forbids coveting the goods of another, as the root of theft, robbery, and fraud, which the seventh commandment forbids. "Lust of the eyes" leads to the violence and injustice forbidden by the fifth commandment. 319 Avarice, like fornication, originates in the idolatry prohibited by the first three prescriptions of the Law. 320 The tenth commandment concerns the intentions of the heart; with the ninth, it summarizes all the precepts of the Law.
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.