"Everyone who looks at a woman lustfully has already committed adultery with her in his heart" (Mt 5:28).
The ninth commandment warns against lust or carnal concupiscence.
The struggle against carnal lust involves purifying the heart and practicing temperance.
Purity of heart will enable us to see God: it enables us even now to see things according to God.
Purification of the heart demands prayer, the practice of chastity, purity of intention and of vision.
Purity of heart requires the modesty which is patience, decency, and discretion. Modesty protects the intimate center of the person. 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.316 For where your treasure is, there will your heart be also.317