Catechism of the Catholic Church 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 Cf. 1 Jn 2:16; Mic 2:2). Avarice, like fornication, originates in the idolatry prohibited by the first three prescriptions of the Law (320 Cf. Wis 14:12). The tenth commandment concerns the intentions of the heart; with the ninth, it summarizes all the precepts of the Law.