“You shall not commit adultery.” (Exodus 20:14)
In God’s sight marriage is holy, and He does not want couples to break up. Nor does He want a marriage to be compromised because of adultery. God goes a step further: if you are married, you may not desire anyone other than your own partner. An outsider may not try to tempt a married person to sin.
In a debate with the scribes, Jesus refines this commandment: “I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart” (Matthew 5:28). Once again Jesus accuses the scribes and pharisees of an interpretation that is too narrow. The seventh commandment should be understood in light of the tenth commandment, “You shall not covet your neighbour’s wife”. (Exodus 20:17). God sees that wrong desires can be evil and defile us (Matthew 15:19).
Jesus’ enemies only judged the outward deed. But Jesus exposes how thoughts and desires are also wrong, just as He condemns hatred as a form of murder. In his dialogue with his friends, Job states that he has made a covenant with his eyes: he has promised himself not to look at another woman (Job 31:1). He says that he has kept his heart pure and God calls him a righteous man. What a beautiful example for men and for women.