Ninth Commandment
“Thou shalt not covet thy neighbor's wife”
WHAT: To covet another person's husband or wife means to entertain impure thoughts about that man or woman. Even if one does not act on such thoughts but simply considers them for one's private pleasure. If such thoughts come to you involuntarily and you try to put them out of your mind, however, that is not a sin.
WHEN: The emphasis is on spiritual desire.
